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THE CAT. 





OF THE LATTER TO THE EXTERNAL TOR*!. 



THE CAT. 



AN INTRODUCTION TO THE STUDY 



OP 



BACKBONED ANIMALS 



ESPECIALLY 



MAMMALS 



Jac kso-n 

By St. GEQBGE \ MIVAKT, Ph.D., F.RS. 



WITH 200 ILLUSTRATIONS 



NEW YORK 

CHARLES SCRIBNER'S SONS 

743 and 745 Bkoadway 

1881 



$1737 

,c* m 

mi ^ 



GIFT 
FATHER 6 RY * N 
AU G- 20, 1940 



L? 



PKEFACE 



Biology is the science which treats of all living 
organisms, from Man to the lowest plant. No natural 
science is at present more keenly pursued or with more 
effect. The advances of Astronomy and Geology have 
produced great changes in men's minds during the last 
three centuries : Biology is producing changes at least as 
great, in the present age. So rapid has been its progress 
that the Natural History of Animals and Plants needs to be 
rewritten — the field of Nature being surveyed from a new 
stand-point. Such a history may be written in two ways : 
(1) Living beings may be treated as one whole, their 
various powers and the more general facts as to their 
organization being successively portrayed as they exist 
in the whole series ; or (2) one animal (or plant) may be 
selected as a type and treated of in detail, other types, 
successively more divergent in structure from the first, 
being described afterwards. 

In following the latter mode, we may either begin with 
one of the most simply organised of living creatures and 
gradually ascend to the highest and most complex in 
structure ; or we may commence with the latter, and 
thence descend to the consideration of the lowest kinds of 
animated beings. 

Historically, it is the latter course which has been 



Tiii PREFACE. 

followed. The bodily structure most interesting to man, 
his own, was the first studied (directly or indirectly), and 
the names now given to different parts of the bodies of the 
lower animals have been mainly derived from human 
anatomy. The descending course is also that which 
seems, on the whole, preferable, for thus, by commencing 
with the class of animals to which man belongs, we may 
proceed from the more or less known to the unknown, and 
from that which is comparatively familiar, to that which is 
strange and novel. 

Having then chosen to begin the study of Animals and 
Plants with that class to which we belong, it might 
perhaps be expected that Man himself would be chosen as 
the type. But a fresh description of human anatomy is 
not required, and would be comparatively useless to those 
for whom this work is especially intended. For a satis- 
factory study of animals (or of plants) can only be carried 
on by their direct examination — the knowledge to be 
obtained from reading being supplemented by dissection. 
This, however, as regards man, can only be practised in 
medical schools. Moreover, the human body is so large 
that its dissection is very laborious, and it is a task 
generally at first unpleasing to those who have no special 
reason for undertaking it. But this work is intended for 
persons who are interested in zoology, and especially in 
the zoology of beasts, birds, reptiles, and fishes, and not 
merely for those concerned in studies proper to the medical 
profession. 

The problem then has been to select as a type for 
examination and comparison, an animal easily obtained and 
of convenient size ; one belonging to man's class and one 
not so different from him in structure but that comparisons 
between it and him (as to limbs and other larger portions 
of its frame) may readily suggest themselves to the 



PREFACE. ix 

student. Such an animal is the common Cat. In it we 
have a convenient and readily accessible object for refer- 
ence, while the advantages which would result from the 
selection of Man as a type will almost all be obtained 
without the disadvantages of that selection. The study 
of the zoology of the Cat, as here treated, will also give the 
earnest student of Biology the knowledge of anatomy, 
physiology, and kindred sciences, which is necessary to 
enable him to study profitably the whole class of animals 
to which it belongs and to which we belong — the class of 
Mammals. The natural history of that entire class will be 
treated of in a companion volume, to which the present 
work may serve as an introduction — all the needful 
anatomical terms and relations (as they exist in the selected 
type) being here once for all explained. The present 
volume Is expressly intended to be an introduction to the 
natural history of the whole group of back-boned animals 
(since they are all formed according to one fundamental 
plan) ; but the subject has been so treated as to fit it also 
to serve as an introduction to Zoology generally, and even 
to Biology itself* the main relations borne by cats, not 
only to the leading groups of animals, but also to plants, 
being here pointed out. The sciences subordinate to 
Biology are also enumerated and defined. 

It has been thought better not to separate the study of 
physiology from that of anatomy, and, accordingly, an 
explanation of the functions performed by each different 
system of parts of which the body is made up, will be 
found to follow the account of their structure. 

I am indebted to my friend Professor Flower for the use 
of his valuable illustrations of the skulls of the Carnivora, 
as also to the Zoological Society, from whose Proceedings 
they are, with some other illustrations, extracted. I 
desire also to express my thanks to Professor Allen 



x PREFACE. 

Thomson, M.D., F.E.S., and to Messrs. Longmans & Co., 
Messrs. Cassell & Co., and Messrs. Kegan Paul & Co., for 
the use of various electros. 

Dr. Murie, F.L.S., has had charge of many of the wood- 
cuts, certain of which — representing ligaments, viscera, 
and salivary glands — have been drawn from his dissections 
and under his supervision. 

I have to thank Mr. Alban Doran, who has made careful 
dissections of the internal ear and portions of the generative 
organs, and also Mr. P. Percival Whitcomb and my son 
Mr. Frederick St. G. Mivart, for more or less assistance. 
To Professor Cope I am much indebted for very kindly 
sending me proofs of unpublished plates of American 
fossils described and named by him. 

I have also to express my obligation to Mr. Win. Pearson 
(of the College of Surgeons) for making some excellent 
dissections, from which certain of the illustrations are 
taken. Original drawings have also been made from 
specimens preserved in the museum of the Eoyal College 
of Surgeons and in the British Museum. The drawings 
have (with the exception of six figures of fossil remains) 
been executed by Mr. C. Berjeau and engraved by Mr. 
Ferrier. I feel bound to express my sense of the skill 
evinced in their execution. 



CONTENTS. 



CHAPTER I. 



INTRODUCTORY. 



SECT. 

1. The Cat as a domestic animal 

2. Its scientific interest 

3. The Wild Cat . 

4. Origin of the Domestic Gat 

5. The Egyptian Cat 

6. The different breeds of the Do 

mestic Cat . 

7. Habits .... 

8. In what the scientific study of 

the Cat consists . 



PAGE 

1 

2 
2 
3 



SECT. PAGE* 

9. The sciences subordinate to 
Biology — different kinds of 
anatomy. . 9 

I 10. Physiology and its subdivisions . 10 

11. Taxonomy .... 11 

12. Hexicology . . . . . 11 

13. Phytogeny . . .11 

14. Order to be followed in this 

Work .... 



15. Chemical composition of the 
Cat's body .... 



11 



12 



CHAPTER II. 



THE CAT S GENERAL FORM. THE SKIN AND ITS APPENDAGES. 



SECT. 


PAGE 


1. The general construction and 


symmetrical relations of the 


Cat's body 


14 


2. The skeleton ... 


16 


3. Connective tissue 


16 ; 


4. Cartilage 


18 ! 


5. Bone ..... 


19 


6. The process of ossification . 


20 


7. The growth of bone 


20 


8. The composition of the skeleton 


21 | 


9. The external skeleton 


21 ! 



SECT. 


PAGE 


10. The epidermis 


21 


11. The dermis 


22 


12. The claws .... 


22 


13. The hair. 


22 


14. Mucous membrane 


24 


15. Epithelium and corium 


26 


16. Teeth 


27 


17. The milk dentition . 


29 


18. Dental formula . 


30 


19. Minute composition of the teeth 


31 


20. Their modes of formation . 


32 



xu 



CONTENTS. 



CHAPTER III. 



THE SKELETON OF THE HEAD AND TKUNK. 



SECT. 


PAGE 


SECT. 


PAGE 


1. The endo-skeleton 


34 


21. The ligaments and mobility of 


2. Its divisions and subdivisions 


34 


the thorax .... 


55 


3. The backbone . 


35 


22. The skull considered generally . 


56 


4. The parts of a vertebra 


35 


23. The occipital bone 


61 


5. Vertebral categories . 


36 


24. The parietal . 


62 


6. The dorsal vertebrae 


36 


25. The frontal. 


63 


7. The lumbar vertebrae 


39 


26. The temporal . 


64 


8. The cervical vertebrae . 


40 


. 27. The sphenoid 


69 


9. The axis .... 


43 


28. The ethmoid . 


71 


10. The atlas .... 


44 


29. The maxillo-turbinal . 


72 


11. The sacrum 


44 


30. The maxilla . 


. 72 


12. The caudal vertebrae * 


46 


31. The pre- maxilla . 


73 


13. The vertebral series as a whole 


47 


32. The malar 


. 74 


14. The ventral part of the spina 


I 


33. The nasal .... 


. 74 


skeleton , 


49 


34. The lachrymal . 


. 75 


15. The sternum 


49 


35. The palatine . 


. 75 


16. The ribs .... 


50 


36. The vomer 


. 76 


17. The costal cartilages . 


52 


37. The mandible 


. 77 


18. The thorax as a whole 


52 


38. Thehyoid 


77 


19. The ligaments and mobility o 


£ 


39. The skull examined externally 




the spinal column . 


52 


internally, and in sections 


! 78 


20. The union of the axis and atlas 


54 


40. The ligaments of the skull 


86 






41. The cranial skeleton as a whole 


. 87 



CHAPTER IV. 



THE SKELETON OF THE LIMBS. 



SECT. 


PAGE 


SECT. 




PAGE 


1. The appendicular skeleton and 


13. 


The femur . 


. 


107 


its divisions, and the bones of 


14. 


The patella 


, 


109 


the pectoral limb 


89 


15. 


The tibia . 




110 


2. The scapula and clavicle 


89 


16. 


The fibula 




112 


3. The humerus . . 


90 


17. 


The tarsus . 




113 


4. The radius . , . . 


93 


18. 


The metatarsus 




115 


5. The ulna .... 


95 


19. 


The phajanges . 


, , 


116 


6. The carpus .... 


96 


20. 


The ligaments of the 


pelvic 




7. The metacarpus 


98 




limb . 


, 


116 


8. The phalanges 


99 


21. 


A general view of the 


pelvic 




9. The ligaments of the pectoral lim 1 


) 100 




appendicular skeleton 




119 


10. A general view of the pectora 


I 


22. 


Comparison of the pectoral and 




appendicular skeleton 


102 




pelvic parts of the appendicu- 




11. The bones of the pelvic limb 


103 




lar skeleton. 


• 


119 


12. The os innominatum 


104 


23. 


The joints . . . 


• ■ 


120 



CONTEXTS. 



xui 



CHAPTER V. 



THE 



SECT. 

1. The muscles in general 

2. Muscular tissue . 

3. Its properties . 

4. Different kinds of muscles . 

5. Their actions . 

6. The classification of muscles . 

7. Muscles of the head and neck 



! CAT B 


MUSCLES. 




PAGE 

. 124 


SECT. 

8. Muscles of the trunk and tail . 


PAGE 

136 


124 


9. Muscles of the fore-limb . 


145 


. 126 


10. Muscles of the hind- limb . . 


154 


128 
. 129 


11. Comparison of the muscles of the 
fore and hind limbs 


163 


. 130 


12. Summary of the Cat':: myology . 


164 


131 







CHAPTER VI. 

THE CATS ALIMENTARY SYSTEM. 



SECT. 


PAGE 


SECT. PAGE 


1. In what alimentation consists 


165 


11. 


The pharynx . . . . 174 


2. Food and waste . 


165 


12. 


The oesophagus . . .175 


3. Intussusception and dialysis 


166 


13. 


The abdominal cavity and its 


4. Crystalloids and colloids . 


. 167 




contents. . . . . 176 


5. Digestion .... 


. 167 


14. 


The stomach . . . .177 


6. Summary of the alimentar 


r 


15. 


The small intestine . .180 


processes and organs 


. 168 


16. 


The caecum and large intestine . 182 


7. Mucus .... 


. 169 


17. 


The pancreas . . . .183 


8. The mouth 


. 170 


IS. 


The liver 384 


9. The tongue .... 


171 


19. 


The peritoneum . . .189 


10. The salivary glands and secretio] 


i 172 







CHAPTER VII. 

THE CAT'S ORGANS OF CIRCULATION. 



SECT. 

1. The essential nature of the cir 

culating system and its com 
ponent parts 

2. The blood .... 

3. Lymph .... 

4. The structure of the arteries 

5. The structure of the veins 

6. The capillaries . 

7. The lymphatics 

8. The heart .... 

9. The great blood- vessels 

10. The divisions of the heart . 

11. The circulation 

12. The valves of the heart 



PAGE 


SECT 


" 


13. 




14. 


. 192 


15. 


. 193 


16. 


. 195 


17. 


. 196 


IS. 


. 196 


19. 


. 197 




. 19S 


20. 


. 199 


21. 


. 201 


22. 


. 201 


23. 


. 203 


24. 


. 204 


25. 





PAGE 


The auricles and ventricles 


205 


The course of the arteries . 


206 


The aorta .... 


206 


The carotid arteries 


208 


The subclavian artery 


209 


The axillary artery 


209 


The thoracic and the abdominal 




aorta ..... 


210 


The iliac artery . . . . 


212 


The external iliac arteries 


213 


The course of the veins 


214 


The portal system . 


216 


The azygos vein . . . 


217 


The lymphatics 


217 



XI V 



CONTENTS. 



CHAPTER VIII. 



THE CAT S ORGANS OF RESPIRATION AND SECRETION. 



The supra-renal capsules . 
The thyroid body 
The thymus 
Other ductless glands .. 
The spleen 
18. The mammary glands . 
Reproduction . 
The male generative organs 
The testis 
Its product 

The female generative organs 
The ovary . 
Its product 



SECT. 


PAGE 


SEC 


1. In what respiration consists 


220 


13. 


2. The elimination of water and 




14. 


the generation of heat . . 


222 


15. 


3. The trachea .... 


223 


16. 


4. The lungs ... . . 


224 


17. 


5. The mechanism of respiration . 


225 


18. 


6. The larynx . . 


226 


19. 


7. The voice .... 


229 


20. 


8. Secretion, in what it consists . 


230 


21. 


9. Waste products 


232 


22. 


10. The kidneys . . . 


232 


23. 


11. The ureters .... 


235 


24. 


12. The bladder . . 


235 


25. 



PAGE 

237 
237 
237 
237 
238 
239 
240 
241 
243 
245 
245 
248 
250 



CHAPTER IX. 

THE CAT'S NERVOUS SYSTEM AND ORGANS OF SENSE. 



SECT. PAGE 

1. Preliminary view of the functions 

of the nervous system . . 252 

2. Sensation 253 

3. The main divisions of the nervous 

system .... 253 

4. Nervous tissue . . . . 253 

5. Membranes of the cerebro-spinal 

axis 256 

6. The spinal cord or myelon . . 257 

7. The brain 259 

8. The nerves . . . .269 

9. The olfactory nerves . . . 270 
The optic nerve . . . 270 
The third and fourth nerves . 271 
The fifth nerve . . . . 271 

13. The sixth and seventh nerves . 273 

14. The eighth nerve . . .274 

15. The ninth, tenth, eleventh, and 

twelfth nerves . . . 274 

16. Summary of the cranial nerves 275 

17. The spinal nerves . . . 276 

18. The brachial plexus and nerves 

of the fore-limb . . . 278 
The plexus and nerves of the 

hind-limb . . . . 281 

The nerves of the tail . . 283 



10. 
11. 
12. 



19. 



20. 



SECT. 

21. The sympathetic system 

22. The organ of touch . 

23. The organ of taste 

24. The organ of smell 

25. The organ of sight 

26. The organ of hearing 

27. Analogies between the ear and 

the eye .... 

28. The function of the nervous 

system generally . 

29. Conditions of its exercise 

30. Thefunctions of the spinal nerves, 

31. The functions of the cranial 

nerves .... 

32. The functions of the spinal cord 

33. The functions of the medulla 

oblongata . . . . 

34. The functions of the pons varolii, 

corpora quadrigemina and 
cerebellum . 

35. The functions of the cerebrum . 

36. The functions of the sympathetic 

system . . ... 

37. Sleep 

38. External and internal sensations 



PAGE 

283 
285 
285 
286 
288 
295 

303 

304 
307 
307 

309 
309 

310 



311 
312 

312 
313 
313 



CONTENTS. 



xv 



CHAPTER X. 



THE DEVELOPMENT OF THE CAT. 



cecx. 


PAGE 


SECT. 


PAGE 


1. 


What is meant by its develop- 




9. 


Of the skull .... 


335 




ment ..... 


317 


10. 


Its ossification 


338 


2 


Change in the ovum antecedent 




11. 


Development of the limbs . . 


339 




to impregnation . . . 


317 


12. 


Of the muscles 


341 


3. 


Actions of the spermatozoa 


318 


13. 


Of the alimentary canal and its 




4. 


Yelk segmentation 


318 




appendages . . . . 


341 


5. 


First appearance of the embryo 




14. 


Of the blood and vascular system 


345 




and the earlier stages of its 
growth ..... 
Nutritive conditions and mater- 
nal modifications . 


320 


15. 


Of the lungs and adjacent parts . 


349 


6. 


326 


16. 


Of the urinary and generative 
systems . .... 


350 


7. 


Development of the tissues . . 


329 


17. 


Of the nervous system and organs 
of sense .... 


355 


8. 


Of the axial skeleton 


332 


18. 


Summary and result . . . 


364 



CHAPTER XL 

THE PSYCHOLOGY OF THE CAT. 



SECT. 


PAGE 


1. 


What the study of Psychology is 


365 


2. 


The Cat's psychical powers 


366 


3. 


Language —its different kinds . 


371 


4. 


Mental powers which are not 






possessed by the Cat 


372 


5. 


All its powers are coordinated . 


374 


6. 


Its hierarchy of functions 


374 


7. 


Its principle of individuation . 


375 


8. 


This cannot be merely nervous 






activity .... 


376 


9. 


Certain anatomical and patho- 






logical facts . . . . 


377 


10. 


The Cat has consentience . 


378 



SECT. 


PAGE 


11. 


The relations of psychical and 






physical phenomena . . 


378 


12. 


The meaning of the term 
' Psyche, ' or ' Soul, ' and the 
question of the existence of 






such an entity 


380 


13. 


Objections considered . . . 


381 


14. 


The Cat not a mere automaton . 


382 


15. 


What the Cat in itself is . 


384 


16. 


Immaterial realities 


385 


17. 


Definitions .... 


386 


18. 


The bearing of Psychology on de- 






velopment . . . 


386 



CHAPTER XII. 

DIFFERENT KINDS OF CATS. 



?ECT. PAGE 

1. What are 'kinds,' 'species,' 

and ' varieties ? ' . .390 

2. Morphological and physiological 

species .... 391 

3. Zoological nomenclature . . 392 



SECT, 

4. 



The Lion, Tiger, Leopard and 

Ounce . . . .392 

The Puma and Jaguar . . . 397 
The Clouded Tiger and Thibet 
Tiger-cat ; the Spotted Cat, 



XVI 



CONTENTS. 



CHAPTER XII— continued. 



the Bay Cat, the Fishing Cat, 
the Leopard-cat, the Wagati 
and the Marbled Tiger-cat . 398 

7. The Serval, the Golden-haired 

Cat, the Grey African Cat, and 

the Servaline Cat . . . 406 

8. The Ocelot, the Margay, Geof- 

froy's Cat, the Ocelot-like 
Cat, the Yaguarondi, the Eyra 
and the Colocollo . . .408 

9. The Rusty- spotted Cat, the Chi- 

nese Cat, the Small Cat, Jer- 
don's Cat, the Java Cat, the 
bushy-tailed-red-spotted Cat, 
the Small -eared Cat, the 
Large-eared Cat, the Plat- 
headed Cat and the Bornean 
Bay Cat . . ' . . . 413 
10. The Egyptian Cat, the Common 
Wild Cat, the Indian Wild 



Cat, the Common Jungle Cat, 
the Ornate Jungle Cat, the 
Steppe Cat, Shaw's Cat, the 
Manul and the Pampas Cat . 

The Northern Lynx, the Pardine 
Lynx, the Thibet Lynx and 
the Caracal \ 

The Common Cheetah and the 
Woolly Cheetah . . . 

Review of living Cats 

Extinct Cats . . . , 

Machserodus .... 
16. Hoplophoneus and Pseudselurus 
] 7. Nimravus and Dinictis . . 

Archaslurus .... 

Pogonodon and Eusmilus . . 

Fossils of uncertain nature, 
and summary of fossil cat 
genera .... 



11 



12. 

13. 
14. 
15. 



18. 
19. 

20. 



419 



424 

427 
430 
431 
432 
433 
435 
436 
437 



437 



CHAPTER XIII. 

THE CATS PLACE IN NATURE. 



SECT. 


PAGE 


SECT. 


PAGE 


1. 


What is needed to be known in 




14. 


The class Reptilia of the pro- 






order to answer the question 






vince Monocondyla 


461 




"What is a Cat ?" . . . 


440 


15. 


The characters by which the Cat 




2. 


The Cat's most general mor- 






differs from all Reptilia . . 


462 




phological and physiological 




16. 


The class Aves or Birds . 


462 




characters .... 


440 


17. 


The characters by which the Cat 




3. 


These distinguish it from all 






differs from all birds, from all 






non-living beings . 


441 




Monocondyla, and from all 




4. 


An objection considered . . 


442 




non-mammalian Vertebrata . 


465 


5. 


The character of the Cat as a 




18. 


The sub- classes and orders of 






living being 


445 




the class Mammalia 


466 


6. 


What is implied in saying "the 




19. 


The characters by which the Cat 






Cat is an animal " 


445 




differs from the sub-classes 




7. 


The principles of zoological 






of Mammalia to which it does 






classification . . . . 


449 




not belong .... 


469 


8. 


The various sub-kingdoms of 




20. 


The characters by which the Cat's 






animals .... 


450 




order differs. from the other 




9. 


The character of the Cat as a 






orders of placental mammals 


471 




backboned animal . 


454 


21. 


The sub-orders and families of 




10. 


The provinces and classes of 






Carnivora . . . . 


474 




backboned animals — espe- 




22. 


The characters of the Cat's sub- 






cially the class of fishes 


455 




order iEluroidea . 


475 


11. 


The characters by which the Cat 




23. 


The families of the Cat's sub- 






differs from all fishes . . 


458 




order . .... 


481 


12. 


The class Batrachia of the pro- 




24. 


The peculiarities of the Cat's own 






vince Branchiata . 


459 




family — Felidse . 


486 


13. 


The characters by which the Cat 




25. 


Position of the genus, Felis, and 






differs from all Batrachians 






the Cat's place amongst all 






and from all Branchiata . 


460 




other creatures 


489 



CONTENTS. 



xvii 



CHAPTER XIV. 

THE CAT'S HEXICOLOGY. 



BECT. 

1. The various relations of living 

creatures to their environment 

2. The Felidae and physical condi- 

tions, such as warmth, light, 
and moisture . . . . 

3. The geography of the Felidae 

4. Zoological geographical regions . 

5. The relations of the Felidae to 

time ..... 



494 



494 
495 

497 



SECT. 

6. Certain elementary facts of 
geology 

7. The palaeontology of the Felidae . 

8. Non-feline mammalian remains 
contemporary with or antece- 
dent to fossil cats 

9. The inter-relations between cats 
and other living creatures 

501 J 10. The parasites of cats 



501 

502 



503 

508 
509 



CHAPTER XV. 



THE PEDIGREE AND ORIGIN OF THE CAT. 



SECT. PAGE 

1. Meaning of the Cat's 'pedigree ' 

and 'origin' . . . 512 

2. No present need to argue in 

, favour of evolution . . 512 

3. Probability of the Cat's descent 

through viverrine ancestors . 512 

4. The probable genetic relations 

or phylogeny of the iEluroidea 513 

5. The probable phylogeny of the 

Carnivora . . . .514 

6. Primitive mammals probably not 

marsupial . . . . 515 

7. Summary of the Cat's pedigree . 517 

8. Premammalian ancestors un- 

known .... 518 

9. Different possible modes of evolu- 

tion 519 

10. What are 'species,' 'genera,' 
' families, ' ' orders, ' and 
1 classes ' ? . . .520 



SECT. PAGE 

11. We have experience of the origin 

of all of these. . . . 521 
What our experience should 
lead us to expect as to the 
origin of Cat species . . 522 
We seem to have experience as to 

the origin of life itself . . 524 
Our experience as to modes 

of origin . . . .524 
Necessity of the idea of an in- 
ternal force . . . . 525 
Psychogenesis . . .526 

The cause of Psychogenesis . . 526 
Prototypal ideas . . .528 
Science is a knowledge of causes, 
and a knowledge of all causes 
is necessary for perfect science 530 
Utility of the study of ' types * . 530 



12. 



13. 
14. 

15. 

16. 
17. 
18. 
19. 



20. 



LIST OF ILLUSTRATIONS. 



External form of Wild Cat and figure of the skeleton, showing the relations 

of the latter to the external form Frontispiece 

FIG. PAGE 

1. Muzzle of the cat, seen in front 14 

2. A diagrammatic vertical section of the cat's body taken anteroposte- 

rior ly through the median plane . . 16 

3. Connective, adipose, and elastic tissue 17 

A. Hyaline cartilage and fibro-cartilage — greatly magnified . . . . 18 

5. Vertical and horizontal sections of a fragment of thigh-bone — greatly 

magnified 19 

6. Vertical section through the thigh-bone of a young cat, showing epi- 

physes 20 

7. Touch-corpuscle and Pacinian body 23 

8. Section of a cat's vibrissa 24 

9. Sole of the cat's fore-paw, showing the pads 25 

10. Similar view of the hind-paw ib. 

11. Ciliated epithelium cells. From Quain's Anatomy . ib. 

12. The cat's dentition 27 

13. Milk dentition of the cat 30 

14. Microscopic tooth structure 31 

15. A fragment of enamel — greatly magnified. From Quain's Anatomy — 

after Kolliker 32 

16. Three views of fifth dorsal vertebra 37 

17. Tenth and eleventh dorsal vertebras ........ 39 

18. Three views of fifth lumbar vertebra 40 

19. Three views of fifth cervical vertebra 41 

20. Five views of axis vertebra 42 

21. Five views of atlas vertebra 43 

22. Three views of sacrum . . 45 

23. Ventral aspect of vertebral column 48 

24. Skeleton of thorax, seen ventrally . 49 

25. First, sixth, and thirteenth ribs 51 

26. Two views of intervertebral discs 53 

27. Ligaments of axis and atlas 55 

28. Dorsal view of skull . .' 56 

29. Base of skull . 58 

30. Front view of skull . 59 

31. Occipital bone — two views , 61 

32. Interparietal bone — two views 62 

33. Parietal bone — two views 63 

34. Frontal bone — two views ib. 

35. Temporal bone— two views 65 



xx LIST OF ILLUSTRATIONS. 

FIG. PAGE 

36. Section of the temporal bone of a tiger. From Professor Flower's paper 

published in the Pro. Zool. Soc. 1869, p. 17 67 

37. Sphenoid bone — two views 68 

38. The right maxilla, seen internally and externally 72 

39. The premaxilla— two views 74 

40. The malar bone — two views * t . . . ib. 

41. The nasal bone — thres views . ....... 75 

42. The lachrymal bone — two views . , ifr. 

43. The palatine bone — three views . . . ib. 

44. The mandible — inside view 76 

45. Ventral and side view of the os hyoides, larynx, and trachea ... 78 

46. Side view of skull 80 

47. Back view of skull 81 

48. Outline vertical section of skull to show cranial angles . . . . 84 

49. Vertical section of skull, showing median ethmoid . ib. 

50. Vertical section of anterior half of skull to show nasal cavity and frontal 

sinus . 86, 

51. Scapula, external aspect 90 

52. Scapula, seen internally and from below . . . • .. . . . 91 

53. Humerus — four views 92 

54. Humerus —inner side .93 

55. Eadius — four views 94 

5C. Ulna — three views 95 

57. Skeleton of fore-paw — its palmar aspect 97 

58. Skeleton of fore-paw — its dorsal aspect . * ib. 

59. Bones of middle digit 98 

60. Vertical section through the bones of the fore-paw of- a young cat — to 

show epiphyses ib. 

61. Ligaments of shoulder — two views . . . . . . . . 100 

62. Ligaments of elbow — two views . . 101 

63. Ligaments of digit — to show the mechanism of the retractile claw . 103 

64. Pelvis — antero-ventral view 104 

65. Os innominatum — outer view 105 

66. Os innominatum — seen from within . ib. 

67. Femur — two views 108 

68. Femur — four views 109 

69. Tibia and fibula— seen in front . . . , . . . .110 

70. Tibia and fibula — seen posteriorly ib. 

71. Tibia seen within, proximally, and distally Ill 

72. Skeleton of hind-paw— plantar surface 114 

73. Skeleton of hind-paw— dorsal surface ib. 

74. Ligaments of knee-joint 117 

75. Vertical section through knee-joint 118 

76. Muscular tissue 126 

77. Muscles of right fore-quarter 136 

78. Muscles of sternum . . . . 139 

79. Muscles of ventral surface of trunk 140 

80. Extensor (dorsal) muscles of right fore-limb 146 

81. Muscles of flexor (ventral) surface of right fore-limb .... ib. 

82. Superficial muscles of outside of right thigh ...... 154 

83. Deep muscles and tendons of outside of right hind-limb. . . . 155 

84. Muscles of inside of right thigh . . . 157 

85. Flexor muscles of leg , , . .159 

86. Surf ace of palate 170 



LIST OF ILLUSTRATIONS. xxi 

FIG. ^GB 

87. Dorsum of tongue 171 

88. Salivary glands 173 

89. Viscera in situ 176 

90. The stomach and pancreas 177 

91. Magnified vertical section of wall of pig's stomach. From Quain's 

Anatomy — after Kolliker 178 

92. Two gastric glands, greatly magnified. From Quain's Anatomy— after 

Heidenhain ib. 

93. Intestinal canal, from oesophagus backwards 179 

94. Intestinal villi — three views 180 

95. Caecum — two views 182 

96. Liver seen from behind 184 

97. Magnified section of an hepatic vein. From Quain's Anatomy — after 

Kiernan 186 

98. Magnified section of a portal canal. From Quain's Anatomy— after 

Kiernan 187 

99. Blood-corpuscles 195 

100. Veins with their valves. From Quain's Anatomy 197 

101. Diagram of a lymphatic gland. From Quain's Anatomy . . .199 

102. Sections of the heart 200 

103. Diagram of the adult circulation (seen dorsally) 202 

104. Great blood-vessels . . 207 

105. Vessels and certain viscera of abdominal cavity 212 

106. Cartilages of larynx 227 

107. The larynx and glottis as seen laterally and above, and both contracted 

and expanded 228 

108. Diagram of different gland forms. From Quain's Anatomy . . . 231 

109. The kidney, entire and in section ........ 232 

110. Diagram of a Malpighian body. From Quain's Anatomy — after Kolliker . 234 

111. Diagram of minute circulation of kidney. From Quain's Anatomy — 

after Bowman ib. 

112. The thymus and thyroid glands ,....'.. 236 

113. The cat's spleen 238 

114. Mammary glands - . . 239 

115. Male generative organs • . ... 242 

116. Diagram of testis. From Quain's Anatomy 244 

117. Spermatozoa 245 

118. Section of cat's ovary, much magnified. From Quain's Anatomy — after 

Schron 248 

119. Another section, still more magnified. From Quain's Anatomy — after 

Schron . . ... 249 

120. The ovum 250 

121. Nerve fibres, magnified. From Quain's Anatomy — after Bidder and 

Volkmann 254 

122. Ganglionic nerve-cells, greatly magnified. From Quain's Anatomy — 

after Valentin 255 

123. Brain of the cat in situ — covered on the left side by the pia mater . . 257 

124. Sections of spinal cord, somewhat enlarged. From Quain and Sharpey 

(Allen Thomson) 258 

125. Lateral view of cat's brain 259 

126. Upper surface of cat's brain . .261 

127. Upper part of cat's brain — the hemispheres much divaricated to show 

the corpora quadrigemina. From a specimen in the College of Surgeons 

Museum . , . . . . , . . . , . 262 



xxii LIST OF ILLUSTRATIONS 

FIG. PAGE 

128. Base of the cat's brain 264 

129. Vertical, longitudinal section of the cat's brain *266 

130. Cranial nerves 272 

131. Brachial plexus and nerves 278 

132. Nerves of fore-paw . 280 

133. Lumbar and sacral plexuses and nerves . . . . . . . ib. 

134. Vertical section of eye 290 

135. Diagram of retina 292 

136. The lens. From Quain's Anatomy — after Arnold. 293 

137. Section through the internal ear 297 

138. Bony labyrinth and auditory ossicles. From specimens in the College of 

Surgeons • .300 

139. Two rods of Corti highly magnified. From Quain's Anatomy . . . 302 

140. Termination of auditory nerves. From Quain's Anatomy — after Max 

Schultze 303 

141. Early stages of yelk segmentation . . 319 

142. Single ovum, more advanced and bisected. From Haeckel's " Evolution 

of Man "•' . .320 

143. Two ova, showing incipient stages of formation of germ area . . . ib. 

144. Section of germ area. From Haeckel's " Evolution of Man " , . . 321 

145. Three views from above of the earliest stages of the embryo's develop- 

ment. From Quain's Anatomy — after Bischoff ib. 

146. More advanced embryo, seen from above, showing proto-vertebrae. From 

Quain's Anatomy 322 

147. Diagram representing four transverse sections of embryo at different 

stages of development , . . 323 

148. Five diagrammatic views of the development of the amnion and allantois. 

From Haeckel's " Evolution of Man " — after Kolliker .... 324 

149. Diagram of the placental connexion of the embryo with the uterus . . 326 

150. The embryo cat in the uterus in its membranes. From Owen's . 

Anatomy of Vertebrates — after Buffon and Daubenton .... 328 

151. Longitudinal section of an embryo. From Quain's Anatomy . . . 332 

152. Diagram of foetus, showing the visceral arches and budding limbs . . 334 

153. Lateral view of head of embryo pig, showing the visceral arches. From 

Quain's Anatomy — after Parker 336 

154. Ventral aspect of the same ib. 

155. Longitudinal, vertical section through embryo, showing incipient ali- 

mentary canal, &c. From Hseckel's " Evolution of Man " — after Baer. 342 

156. Diagram of the foetal arteries and veins 347 

157. Diagram of the foetal circulation through the heart and aorta . , . ib. 

158. Diagram of the development of the generative organs .... 353 

159. Portion of ovary of kitten, showing first development of ova — from 

Foulis 355 

160. Diagram of the development of the brain 357 

161. Four figures of the brain of an embryo kitten. From Quain's Anatomy, 

— after Reichert . . . .... 358 

162. Development of the eye — from Quain's Anatomy . . . . . 362 

163. A Radiolarian (Dorataspis polyanastra) — greatly magnified . . . 378 

164. The same, only partially developed — (Both from the Journal of the 

Linnean Society) 379 

165. Skull of the Leopard— from Pro. Zool. Soc 395 

166. The Ounce {Felis uncia) — from Mr. Elliot's Monograph . . . . ib. 

167. Skull of the Ounce— from Pro. Zool. Soc. ....... 396 

168. The Clouded Tiger (F. macrocelis) 398 



LIST OF ILLUSTRATIONS. xxiii 

FJG. PAGE 

KJ9. Skull of the Clouded Tiger— from Pro. Zool. Soc 399 

170. The Fishing Cat (F viverrina)- after Elliot . _ 402 

171. Skull of Fishing Cat— from Pro. Zopl. Soc ib. 

172. Skull of the Leopard- Cat— from Pro. Zool. Soc 403 

173. The Marbled Tiger-Cat (F marmorata) 405 

174. Skull of Gcoffroy's Cat— from Pro. Zool. Soc 411 

175. The Eyra (F. Fyra) 412 

176. The Rusty-spotted Cat (F. rubiginosd) — after Elliot 415 

177. The Flat-headed Cat (F planiceps)— after Elliot 418 

178. Skull of Flat-headed Cat— from Pro. Zool. Soc. ib. 

179. The Manul (F. Manul) — from a specimen in the British Museum . . 423 

180. The Northern Lynx, variety F.maculata — from a specimen in the British 

Museum 425 

181. The Cheetah ( Cyruelurusjubata) 428 

182. The young Cheetah ib. 

183. Skull of Cheetah (De Blainville) 429 

184. Skull of MacJicerodus smilodon, (De Blainville) 433 

185. Skull and teeth of Hoplophoneus oreodontis {Cope) 434 

186. Skull of Nimravus bracliyopa (Cope) ib. 

187. Skull of Diniatis cyclops (Cope) 435 

188. Skull of ArclicBlurus debilis (Cope) 436 

189. Skull of Pogonodon platycopis ( Cope) 437 

190. Lower jaw and teeth of Evsmilus bidentatus 438 

191. Skull of the Panda (Ailurus fulgens) — from the Pro. Zool. Soc. . . 474 

192. Skull of the bear (Ursus arctos) — from the Pro. Zool. Soc 475 

193. Basis cranii of the bear. From Professor Flower's paper on the Carni- 

vora, Pro. Zool. Soc 476 

194. Vertical section of the tympanic cavity of the bear — from Professor 

Flower's paper 477 

195. Skull of an Indian fox ( Vulpes bengalensis) — from the Pro. Zool. Soc. . 478 

196. Basis cranii of wolf — from Professor Flower's paper ib. 

197. Section of auditory bulla of dog — from Professor Flower's paper . . 479 

198. Skull and dentition of Paradoxurus Crossii— from Pro. Zool. Soc. . . 480 

199. Basis cranii of civet — from Professor Flower's paper .... 481 

200. Basis cranii of Paradoxure — from the same paper ib. 

201. Basis cranii of ichneumon — from the same paper 482 

202. Basis cranii of hyaena — from the same paper 484 

203. External form of Cryptoprocta 485 

204. Skull of Cryptoprocta — after Milne-Edwards ib. 

205. Basis cranii of Cryptoprocta — from Professor Flower's paper . , 486 

206. The pads of the feet of Cryptoprocta— after Milne- Edwards . . . ib. 

207. Basis cranii of tiger — from Professor Flower's paper .... 487 

208. Section of tiger's auditory bulla (Fig. 36 repeated) 488 

209. Diagram of cat's possible pedigree 518 



THE CAT. 



CHAPTEE I. 



INTRODUCTORY. 



§ 1. Whether it is the Cat or the Dog which is the most 
domestic of all our domestic animals, is a question which may be 
disputed. The greater intelligence and affection of the dog, cause 
men generally to prefjfcit to its rival. As the eager partner of our 
sports, or the faithjjj guardian of house or homestead, it is of 
especial value. YeF^he cat is so largely self-supporting and so 
useful an ally against unwelcome intruders, that it is the inmate 
of a multitude of humble homes wherein the dog has no place. 
The cat also is favoured by that half of the human race which 
is the more concerned with domestic cares ; for it is a home-loving 
animal and one exceptionally clean and orderly in its habits, and 
thus naturally commends itself to the good will of the thrifty 
housewife. 

Moreover, though it is generally much less demonstrative in its 
affection than is the dog, yet cats differ as men do, and some in- 
dividuals manifest strong feelings of regard for one or other members 
of the family wherein they make their homes. 

Cats are even sometimes made use of to obtain food for their 
owners, the latter availing themselves of the habit which cats have 
of bringing home prey.* 

The Domestic Cat is an animal so common and familiar that its 
utility is sometimes apt to be lost sight of. To realise its usefulness 
we must imagine ourselves in a land wbere no such an animal is 
known, but where the annoying creatures upon which it preys shall 
have multiplied with that rapidity natural to them. The familiar 
tale of Whittington may serve to illustrate what would be the effect of 
its introduction into such a land. It has been calculated that a single 
cat may devour twenty mice in one day ; but this of course is by 

* Thus, several rabbits will sometimes be brought home by a eat in a single day. 



2 THE CAT. [chap. i. 

no means the limit of its powers of destruction. Its effect in putting 
to flight the creatures it pursues, is again far in excess of its 
destructive energy. Were every cat in England simultaneously 
destroyed, the loss through the entailed increase of vermin would 
be enormous. 

§ 2. But however much this animal may deserve our esteem, or 
win our admiration, by its shapely form and graceful movements, 
it certainly has very special claims on the attention of lovers of 
biological science. For in the first place its organization, considered 
absolutely in itself, is one of singular perfection, and the adaptation 
of means to ends which it displays is truly admirable. If, however, 
we compare its organization with that of other animals, we shall by 
so doing not only gain a better appreciation of its structural per- 
fections, but also become acquainted with a variety of relations 
conveying useful lessons in anatomy, psychology,* and zoology, and 
others referring to the past, the present, and even the future history 
of this planet. 

§ 3. The " Common " (domestic) Cat of our country, and indeed 
of the continent also, is not the " Common Cat " of zoology. The 
latter is of course the originally native cat — or wild cat. The 
domestic and the wild cat may, however, for our present purpose, be 
considered together, and, thus considered, the events of the last two 
thousand years have strangely altered the disBfcution of the cats of 
this country. "\ 

That men dwell in cities, instead of in woods, is one effect of 
civilization. A similar but greater change has been produced with 
English cats by the same cause. For when Julius Caesar landed 
here our forests were plentifully supplied with cats, while probably 
not a single mouser existed in any British town or village. . The 
word "cat" appears to be of Roman origin, being probably derivedfrom 
the Latin word cat us, which word also seems to have been at the same 
time the root of the Greek Karra, the old German name chazza, and of 
the softened French form of the word, chat. The original derivation 
of the name does not, however, appear to have been as yet ascertained. 
It occurs in Anglo-Saxon writings with the spelling Catt. 

It might be supposed that our present domestic cat is simply our 
own ancient wild cat tamed ; but had it been so and therefore been 
easily procurable, it would not have been so highly valued as it was 
even so late as a thousand years after the Roman invasion. But 
though the domestic cat w 7 as thus rare, and therefore precious, the wild 
cat continued to be common in England during the Middle Ages. 
This is proved by the fact that its fur was then commonly used for 
trimming dresses. 

A canon, enacted in the year 1127, forbad any abbess or nun to 
use more costly fur than that of lambs or cats, and the cat was an 
object of chase in royal forests, as is shown by a license to hunt it of 

* The word Psychology is here used in i its proper sense as embracing Physiology 
its wide and (as the author believes) in J within its scope. 



CHAP. I.] 



INTRODUCTORY. 



the date 1239, and by a similar charter given by Richard the Second 
to the Abbot of Peterborough. 

The Wild Cat is now (thanks to the destruction of our forests, 
the introduction of fire-arms, and the over-zeal of game-keepers,) 
extinct in England, and perhaps in Wales also, though it lived 
here till within fifty, and in Wales till within twenty years ago. In 
Ireland it seems never to have existed, and the stories we read of 
Irish wild cats probably refer to the progeny of domestic cats run 
wild. This is the opinion of Dr Hamilton, F.Z.S., who has paid 
great attention to this subject, and carefully collected and investigated 
the evidence as to the existence of the wild cat in Ireland. In Scotland 
it is still far from uncommon, and is especially frequent in Inverness, 
Ross-shire, Sutherland, and on the west coast of the Highlands, where 
the recent increase of rabbits (animals so useful to it as good food,) 
seems to have occasioned some increase in the number of wild 
cats. These animals exist also in Skye, but not in the Western 
Isles. 

On the continent the wild cat is found in Southern Russia, and 
the adjacent parts of Asia, Turkey, Greece, Hungary, Germany, 
Dalmatia, Spain, Switzerland, and, though now very rare, France.* 
It does not appear to exist in Norway or Sweden. 

§ 4. Our Domestic Cat seems to have come to us (like our other 
domestic animals) from the East, and is probably a descendant of 
the old domestic cat of Egypt, which, as the granary of the ancient 
world, might well have been the country in which the animal was 
originally tamed. In the Egyptian Gallery of the British Museum 
is an excellent painting of a tabby cat, which seems to be aiding a 
man who is capturing birds. It is mentioned in inscriptions as early 
as 1684 B.C., and it was certainly domesticated in Egypt thirteen 
hundred years before Christ. The earliest known representation of 
the cat as a domestic animal and pet, is at Leyden in a tablet of the 
18th or 19th dynasty, wherein it appears seated under a chair. 
In Egypt, it was an object of religious worship and the venerated 
inmate of certain temples. The goddess Pasht or Bubastis, the 
Goddess of Cats, was, under the Roman Empire, represented with a 
cat's head. A temple at Beni-Hassan, dedicated to her, is as old as 
Thothmes IY. of the 18th dynasty, 1500 B.c.f Behind that temple 



* One wild cat at the least has been 
killed in France between 1815 and 1830. 

f Dr. Birch has kindly informed me 
that the earliest representation of the cat, 
with which he is acquainted, the date of 
which is certain, is on tomb No. 170 
of the Berlin Museum, apparently of 
about 1600 B.C. ; but that it also figures 
on a tablet which from its style appears 
to be two hundred years older — as part 
of the name of a woman, " Main " or 
cat. It also appears in hunting scenes 
of the 18th dynasty, and in rituals 
written under that dynasty, but pro- 



bably repetitions of a much earlier text. 
It is mentioned in the 17th chapter of 
the Eitual, and the coffins of the 11th. 
dynasty are inscribed with that chapter, 
which, according to Lepsius, would carry 
us bnck to about 2400 B.C. In a copy of 
the Ritual of B.C. 1500, its 33rd chapter 
has the text, "thou hast eaten the rats 
hateful to Ea (the Sun), and thou feedest 
on the bones of the impure cat." In 
Egypt an animal, though sacred in one 
city, might be regarded as impure in 
another city. 



THE CAT. 



[chap. i. 



are pits containing a multitude of cat mummies. The cat was an 
emblem of the sun to the Egyptians. Its eyes were supposed 
to vary in appearance with the course of that luminary,* and 
likewise to undergo a change each lunar month, on which account 
the animal was also sacred to the moon. Herodotus (h\ 66) re- 
counts instances of the strangely exaggerated regard felt for it by the 
dwellers on the Nile. He tells us that when a cat dies a natural 
death in a house, the Egyptians shave off their eyebrows, and that 
when a fire occurs they are more anxious to save their cats than to 
extinguish the conflagration. 

From Egypt it must have been introduced into Greece, and the 
intimate knowledge of Egyptian customs which became common in 
Rome from the time of Julius and Augustus must have brought 
into it amongst many other animals a knowledge of the domestic 
cat. A fresco painting of such a cat was discovered in Pompeii, f 

It was not a domestic animal amongst the Hebrews, though it was 
known in India two thousand years ago. 

It has been suggested by Professor Rolleston,J that the domestic 
animal of the Greeks (used by them for the purposes for which we 
now use the cat) was the white -breasted marten. But however 
this may be, there can be no question as to the cat having been 
domesticated in Europe before the Christian era. There are 
signs that it was domesticated amongst the people of the Bronze 
period, and the supposition that it was first introduced into Western 
Europe by the Crusaders, is of course an altogether erroneous one. 
They may however have introduced a distinct race, for if it be true 
that our domestic cats have mainly descended from the Egyptian 
cat, it does not follow but that blood from other sources may have 
mingled with that of the Egyptian breed. 

Pope Gregory the Great, who lived towards the end of the sixth 
century, is said to have had a pet cat, and cats were often inmates 
of nunneries in the Middle Ages. The great value set upon the 
cat at this period is shown by the laws which in Wales, Switzerland, 
and Saxony, and other European countries, imposed a heavy fine on 
cat-killers. As compensation, a payment was required of as much 
wheat as was needed to form a pile sufficient to cover over the body 
of the animal to the tip of its tail, the tail being held up vertically, 
with the cat's muzzle resting on the ground. 

The Wild Cat (Felis catus) differs from our ordinary domestio 
cat in that it is more strongly built and larger, with a stouter head 
and shorter and thicker tail, which is not tapering but of about the 
same thickness throughout. Its whiskers also are more abundant, 
and the soles of its feet are, in the males, deep black. Its body is 
of a yellowish- grey colour, with a dark longitudinal mark along the 



* Mr. J. Jermer "Weir has found that 
the eyes of cats will really change colour. 

f See Plate 81 of Kaccolta de piu belli 
Dipinti, from the colled ions in the Royal 
Muaeum (Napoli, 1854). The cat is 



represented as seizing a thrush, and is 
very well drawn. 

X See Cambridge Journal of Anatomy 
and Physiology, 1868, vol. ii. pp. 47 and 
437. 



chap, i.] INTRODUCTORY, 5 

back, and with numerous darkish stripes descending more or less 
vertically down the sides, and marking transversely the limbs. Its 
tail is ringed with black, and is black at tbe end. It is thus marked 
like the domestic variety called "tabby." One killed near Cawdor 
Castle measured 3 feet 9 inches from its nose to the end of its tail.* 
Its savage disposition is very early shown, even the young kittens 
spitting vigorously at anyone who approaches them. Tbe female 
makes her nest in hollow trees and the clefts of rocks, and sometimes 
uses the deserted nest of some large bird. 

§ 5. The Egyptian Cat (Felis maniculata) is a native of northern 
Africa, and was the parent of the cat tamed by the Egyptians, and 
— if what has been here urged is correct — also of our own domestic 
cat. possibly ^with an admixture of other blood. 

The Egyptian cat is said to be about one-third smaller than the 
European wild cat. It is of a yellowish colour, somewhat darker 
on tbe back and whitish on the belly. There are some obscure 
stripes on the body, which become more distinct on the limbs. The 
tail is more or less ringed towards its termination, which is 
black. 

§ 6. Although the differences between the various breeds of the 
Domestic Cat are small indeed compared with those between dif- 
ferent races of dogs, still very distinct varieties exist, but their 
distinctions repose mainly on the colour and the length or quality of 
the fur, and not on differences of form, such as those we find 
existing between the Greyhound and the Pug, the Spaniel and the 
Mastiff. 

The colours of cats may be divided into black, white, tabby, sandy 
tortoisesbell, dun, grey, and what is termed " blue." There are also 
cats in which these various colours are more or less mixed. 

The grey cat is very rare. It is, in fact, a tabby, without the 
black stripes, except two large stripes over the fore-legs — marks 
present in most spotted or striped cat-like animals of whatever 
species. 

Black cats are remarkable for the clear yellow colour of their 
eyes. Their coat is rarely entirely black, for there are generally 
a few white hairs on the throat at the least. When young they 
show more or less perceptible striped markings. 

White cats may have blue eyes, or eyes of the ordinary colour — 
that is, an obscure yellow with a tinge of green. 

Those with blue eyes are generally deaf, but they are not always 
so. It often happens that the eyes of a white cat are not alike in 
colour ; thus one may be blue and the other yellow. 

The late Mr. John Stuart Mill told my friend Mr. John Jenner 
Weir, F.L.S v f that he had at Avignon a breed of cats the eyes of 
which distinctly changed colour when the animals were excited. 

Mr. Harrison "Weir tells me that the j at numerous cat shows, and I am in- 
largest domestic cat he has seen weighed i debted to him for very kindly furnishing 
twenty-three pounds. me with his notes respecting varieties of 
+ This gentleman has acted as judge 1 the domestic cat. 



THE CAT. 



[CHAP. I. 



The tabby cat may be the result of the occasional crossing ot the 
domestie cat by the wild cat. That they do breed together occasion- 
ally is certain,* and indeed races of domestic cats of different parts 
of the world will breed with wild cats of the same region. 

The tortoiseshell cat should be fawn-coloured, mottled with black. 
Cats thus marked are almost invariably females, while sandy-coloured 
cats are almost always males. It appears that the sandy torn cat is 
the male of the breed of which the tortoiseshell is the female — the 
litters being almost invariably so divided. This fact is very interest- 
ing, because the sexes of cat-like animals are similarly coloured.! 

Sometimes, however, sandy cats are female, and there is at least 
one good instance of a true tortoiseshell torn cat. Such cats, indeed, 
have not unfrequently been offered, by letter, to the Secretary of the 
Zoological Society, at very extravagant prices. Probably many of 
them were male cats of three colours — such as white and tortoiseshell 
and grey- white and sandy — but not the true tortoiseshell. 

The Royal Siamese cat is of one uniform fawn colour, which may 
be of a very dark tinge. There is a tendency to a darker colour 
about the muzzle — as in pug dogs. It has also remarkable blue 
eyes, and sometimes, at the least, two bald spots on the forehead. 
It has a small head. 

The blue or Carthusian cat is a breed with long, soft hair of a uniform, 
dark greyish-blue tint, with black lips, and black soles to the paws. 

The Angora, or Persian cat, is remarkable for its great size, and 
for the length and delicacy of its hair, especially of the belly and 
throat. Most commonly its coat is of a uniform white, yellowish 
or greyish colour, while the soles of its paws and its lips are often 
flesh-coloured. Its temperament is said to be sometimes exception- 
ally lethargic ; but this is certainly not always the case, and may 
be due to excessive petting for generations. This breed is believed 
by some naturalists to be descended from an Asiatic wild cat,:£ with 
a shorter tail than that of the Egyptian cat. It is commonly re- 
peated in works on Natural History that there is in China a breed 
of cats with pendent ears ; but the Pere David § regards the 
assertion as an absurd fable. He has repeatedly sought to find 
such animals, but has never been able to see any, or to learn that 
they existed. 



* This has been ascertained by Mr. A. 
H. Wills, who succeeded in getting the 
wild and domestic cat to breed together 
in confinement. (See Land and Water, 
Sept. 4th, 1875 ; and the Zoologist for 
1873, p. 3574 ; and for 1876, pp. 4867 
and 5038.) Mr. S. C. B. Pusey has abo 
successfully crossed the wild and domestic 
cat, and several kittens resulting from 
this cross have been sent to the gardens of 
the Zoological Society of London. This 
interbreeding is remarkable, seeing that 
the period of gestation of the wild cat is 
sixty-eight days, or twelve days longer 



than that of the domestic animal. 

f The only exception I have met with 
is the Yaguarondi of America, in which 
species the female is said to be of a 
lighter and brighter colour than the 
male. 

X Pallas says that cats like the Angora 
cat are brought to Siberia from China. 
Zoographia Russo-Asiatica, vol. i. p. 28, 
note 3. 

§ The well-known Lazarist missionary 
and naturalist, who has made so many 
interesting discoveries in China and 
Thibet. 



CHAP. I.] 



INTRODUCTORY. 



In Pegu, Siam, and Burmah, there is a race of cats* — the Malay 
Cat — with tails only of half the ordinary length, and often contorted 
in a sort of knot, so that it cannot be straightened, f The true short- 
tailed or tailless cat — the Manx Cat — has also the hind-legs relatively 
long. Mr. J. J. Weir tells me he has seen one which had the fore- 
legs so short as to be useless in walking, and the animal sat up like 
a kangaroo. { 

Tailless cats are not, however, the only cats to be found in the 
Isle of Man ; some cats there have tails ten inches long,§ a fact 
probably due to the introduction of long- tailed cats from England, 
Scotland, or Ireland. In cross-breeding the progeny seem generally 
to resemble the father as to length of the tail- jf A tailless breed of 
cats also exists in -the Crimea. The Mombas Cat of the coast of 
Africa is said to be ^[ covered with short stiff hair instead of the 
ordinary sort of hair. The Paraguay Cat ** is but a fourth of the 
average size of our domestic cats, has a long body with short, shiny, 
scanty hair, which lies close, especially on the tail. In South 
America there is said to be also a race of cats which have ceased to 
give forth cries like those by which our own cats are wont to give 
expression to their emotional sensibility. It is to be wished that 
this last breed should be introduced into this country. Yet the 
breed would probably not persist, for the reason which seems to 
limit the formation of new races ; for the wandering nocturnal 
habits of the species defeat most attempts at selection in breeding. 

That variations which might serve for the formation of new breeds 
must be every now and then forthcoming, is indicated by such facts 
as the following one, for a knowledge of which I am indebted to Mr. 
John Birkett. 

A female cat had its tail so injured by the passage of a cart-wheel 
over it, that her master judged it best to have her tail cut off near 
the root. Since then she has had two litters of kittens, and in each 
litter one or more of the kittens had stumps of tails, while their 
brothers and sisters had tails of the usual length. Mr. Birkett 
himself saw one of the stump-tailed kittens. It is of course pos- 
sible that the mother had some trace of Manx blood in her, but it is 
not likely, and the occurrence of the phenomenon just after, and 
only after, the accident and amputation, seems to indicate that in 
this perpetuation of an accidentally deformed condition, we have an 
example of the origination of a new variety. 



* See J. Crawford's Descriptive Dic- 
tionary of the Indian Islands, p. 255. 

+ Its contortion is due to deformity of 
the bones of the tail. 

X In the Museum of the Royal College 
of Surgeons there is preserved the skele- 
ton of a cat, formerly belonging to the 
late Mr. Doubleday, the entomologist. 
This cat was born without any fore- 
limbs, yet could jump so well as to be 
able to jump up on a table. All the 



bones of the fore-limb are entirely want- 
ing, save the shoulder-blades. 

§ Mr. Bartlett assures me he has 
measured cats' tails in the island, and 
found all lengths up to ten inches. 

|| See Mr. Ortou's Physiology of Breed- 
ing, 1855, p. 9. 

*| Sec Captain Owen's Narrative of 
Voyages, vol. ii. p. 180. 

** See Reugger's Saugethiere van Para- 
guay, 1830, p. 212. 



8 THE CAT. [chap. i. 

The direct influence of external circumstances upon different kinds 
of cats is worthy of note. Thus Captain Owen, R.N., (already re- 
ferred to), tells of a cat which, having been taken to Mombas, " under- 
went a complete metamorphosis/' and " parted with its sandy- coloured 
fur " after only eight weeks' residence there. In Paraguay, again, 
cats seem unable to become thoroughly feral as they do in other 
places, and as other European animals do in Paraguay. 

§ 7. The domestic cat begins to be ready to reproduce by the end of 
the first year of her life, and she is prolific to her ninth. Her young 
are carried for fifty-five or fifty-six days, and she generally has five 
or six young at a birth, and sometimes eight or nine. In a wild 
state the cat brings forth at least twice a year, but the domestic cat 
will do so three or four times annually. The wild cat has only four 
or five young in a litter. The length of life which cats attain varies 
with individuals, and is a point difficult satisfactorily to ascertain. 
It seems probable that about twelve years is its ordinary limit, but 
in some cases the age of eighteen years may certainly be attained 
under favourable circumstances. 

Though small quadrupeds and birds are their natural prey, cats 
are singularly fond of food which in a wild state they can never or 
but seldom attain, namely, cow's milk, and also fish. In spite also 
of the relative obtuseness of their sense of smell, they are said to 
show a marked preference for certain odours, a taste in harmony 
with that luxurious and ease -loving nature with which they are 
endowed. 

§ 8. To know all about the history and habits of the cat, together 
with the peculiarities of form and colour of its various breeds, both 
wild and domestic, is not to have a scientific knowledge of the cat. 
To know the animal scientifically, we must be able to answer cor- 
rectly the question " What is a cat ? " But we cannot so answer 
this question unless we know both the main facts as to the animal 
considered in itself absolutely, and the various leading relations in 
which it stands to all other creatures. 

" We understand a particular kind of animated being, when 
looking inwards we see how its parts constitute a system, and again 
looking outwards and around, how this system stands with regard 
to other types of organised existence." * 

No object can be understood by itself. We comprehend anything 
the better, the more we know of other things distinct from but related 
to it. 

The complete natural history of any animal, in the full and 
proper sense of the term, is its Biology. It is so because, though 
the study of any animal is of course mainly its zoology, yet 
fully to understand certain of its powers, and the conditions 
necessary for its existence, a side glance should be cast at the 
vegetable world also ; and Biology is the term which denotes the 
science of all living creatures — both animals and plants — and there- 

* Essays by James Martineau, Second Series, p. 417 



chap. 1] INTROB UCTOB Y. 9 

fore embraces within it both zoologij and botany. Moreover, Biology 
not only includes these two subordinate sciences, but also the various 
inquiries which refer to the relations which exist between their 
respective subject-matters. 

Now, in the first place, the study of the cat, as of every living 
creature, may be followed up along two different lines of inquiry. 
One of these refers to the structure of its body, the other refers to 
the actions which its body performs ; in other words, the animal 
may be considered statically or dynamically. 

Before, however, considering these two kinds of inquiry, and 
seeing what subordinate inquiries they respectively include, it may 
be well to note that the cat's body is obviously a complex structure, 
consisting of distinct parts, which are also obviously put to different 
uses, and reciprocally minister one to another. Thus, for example, 
the limbs may more or less rapidly propel the body after prey which 
the eyes guide the paws to grasp and bring to the teeth and jaws 
by which it is divided to pass into the interior of the trunk, to be 
there converted by the digestive organs into nutriment, by which 
the limbs, the eyes, the paws, the teeth and jaws, stomach, intes- 
tine, &c, are themselves supported and maintained in healthy 
working condition. This animal's body, then, is a complex whole in 
which all the parts are reciprocally ends and means ; and such is the 
definition of " an organism," wide as is the difference in complexity 
between organisms, both animal and vegetable, of very different 
kinds. 

§ 9. The organism with which we are occupied, the cat's body, 
may, as has been already said, be considered as to its structure 
and as to its actions. As to its structure it may be considered with 
respect to its size, shape, consistency, the number, form, and relative 
position of its various parts, and such study is called Anatomy. The 
inquiry as to its form is called Morphology, and this inquiry may 
be directed to its larger parts and grosser structures or to its minute 
structure. 

The various parts of the cat's body, such as its tongue, eyes, 
stomach, kidneys, &c, are termed " organs," and these are grouped 
together into different "sets" or "systems." Thus, e.g., we have 
the alimentary system of organs made up of the mouth, oesophagus, 
stomach, and intestine — or alimentary tube — with the various organs, 
liver, pancreas, &c, which are directly connected with that tube. 
But every organ is made up of several different animal substances, 
variously blended, and differing in their minute or microscopic 
characters. The study of such minute structure — such microscopic 
anatomy — is termed Histology. Each of the various substances 
thus minutely differing, and which build up the organs of the body, 
is called a tissue, and Histology is, therefore, the science of the 
tissues of which every living creature may be composed. Histology 
enables us to understand the structuie and nature of the ultimate 
substance or parenchyma of the body, as far as our powers of observa- 
tion at present extend ; but those powers are very imperfect, and 



10 THE CAT. [chap. i. 

are very far from enabling us really to understand the absolutely 
ultimate composition of the body. 

Another science which concerns the structure of the body is 
Comparative Anatomy. By it the structure of the whole body or of 
any part of the body is compared with the bodies or corresponding 
parts of the bodies of other creatures. The comparative anatomy 
of animals is sometimes called Zootomy. The above inquiries all 
refer to the number, shape, arrangement, connexion and relative 
position of parts (whether large or minute), and to the resemblances 
and differences between different living creatures thus regarded. 

The inquiries which constitute the next set of Biological sciences, 
refer to the actions which the cat's body performs. 

Obviously the animal moves, takes food, and, if young, increases 
in size. The slightest observation convinces us that it has senses, 
feelings, and emotions, more or less similar to our own. If emaciated 
by starvation we see that it can by food regain its former bulk, and 
we may observe that trifling wounds or injuries may be repaired. 
Others of its actions normally result in the production of a new 
individual — another generation. In short the animal lives. These 
activities are, as we all know, shared by other animals, and some 
of them by plants also, which grow and rep air certain injuries — 
replacing lost parts — and reproduce their kind. 

§ 10. The term usually employed to denote the study of the bodily 
activities, or functions generally, is Physiology. 

This study is made up of various subordinate inquiries. We 
may consider the functions of each tissue, of each organ, and of each 
system of organs. Thus we have, e.g., the study of the actions of the 
system of organs which nourish and support the body : i.e., the 
study of the function of sustentation. We have again the study of 
that system of organs which serves to continue the race, i.e., the 
study of the function of reproduction. 

We shall hereafter see that the former function is performed by 
various organs destined respectively to receive and digest food, to 
distribute about t hebody the nutritious matter obtained from it, to 
breathe and to form or secrete certain products. These functions, 
therefore, are those of (1) alimentation, (2) circulation, (3) respiration, 
and (4) secretion. 

But a creature, such as our type the cat, not only lives and repro- 
duces, it is also active, and executes a great number of apparently 
voluntary and other actions, and has a power of experiencing a 
variety of sensations. The functions then of (1) motion, and (2) 
sensation, form other subjects of physiological inquiry. 

The last two functions are called the animal functions.* The 
functions which minister to sustentation and reproduction, as they 
are found in all living creatures, plants as well as animals, are 
called the vegetative, or vegetal, functions. 

* Because sensation does not exist in i spicuous powers of motion are special 
any plant, while locomotion and all con- | animal endowments. 



chap, i.] INTRODUCTORY. 11 

Yet another and a somewhat peculiar study, is the study of 
development. It is a study at once morphological and physiological. 
For it is the study of the changes which the animal passes through 
in proceeding from its first condition, as a germ, to its adult stage 
of existence. It is, therefore, a study of form and a study of an 
active process both together. 

It is also desirable not only to note the function of each organ 
and set of organs, but also to consider the activity of the animal as 
a whole — the physiology of the individual or Psychology. 

§ 11. But we shall be quite unable to answer the question, What 
is a cat ? if we do not learn the relations in which it stands to other 
living creatures — its position in the general scheme of things : in 
other words, the cat's place in nature. 

We must therefore compare the cat with all other living creatures ; 
but especially with those which resemble it the more nearly. But 
to do this we must first understand more or less what the general 
scheme of organic nature is, that is to say, we must learn something 
of the arrangement and classification of living beings, i.e., of the 
science of Taxonomy. 

§ 12. Every animal and plant (and therefore, the cat and the cat 
tribe) has certain definite relations to space and time. Its geo- 
graphical distribution and its past history, as shown by fossil remains, 
also form indispensable matters of inquiry, and respectively pertain 
to the sciences of Organic Geography and Palaeontology. But every 
living creature has also relations with other living creatures, which may 
tend to destroy it or indirectly to aid it, and the various physical forces 
and conditions exercise their several influences upon it. The study 
of all these complex relations to time, space, physical forces, other 
organisms, and to surrounding conditions generally, constitutes the 
science of Hexicology* 

§ 13, But there is yet one more inquiry, without which any 
modern work on zoology would be quite incomplete, and that is a 
genealogical investigation, the prosecution of which pertains to the 
science of Phytogeny. This science (assuming the truth of the 
doctrine of evol ution) f investigates the evidence as to the various 
ancestral forms through which any now existing organism has 
probably passed in its descent from the most remote organisms 
which can, with any degree of probability, be regarded as its an- 
cestors. We must then, finally, endeavour to gain what light we 
may as to the first origin of that form of life which has been chosen 
for study — in other words we must investigate the cat's probable 
pedigree. 

§ 14. It appears to the writer that the study of the cat's anatomy 
and physiology may be best pursued by considering the function 



* e^s— habit, state, or condition. 

t The doctrine of evolution teaches 
that each existing kind of animal or 
plant was originally derived by a natural 



process of generation from other animals 
or plants more or less different in kind 
from it. 



12 TEE CAT. [chap. i. 

of each organ and set of organs, together with their structure, and to 
treat of them in the following order : — 

I. The skeleton, both external and internal. 
II. The parts which act upon the skeleton to effect motion — the 
muscles. 

III. The organs of alimentation. 

IV. The organs of circulation. 

Y. The organs of respiration and secretion. 
VI. The generative organs and reproduction. 
VII. The nervous system and organs of sense. 
VIII. The development of the body. 
IX. Psychology. 

The facts of structure and function having been disposed of, we 
may proceed to consider the various affinities of the cat to other 
animals, its relations to space and time, and the question of its 
origin. 

§ 15. Before, however, commencing the proposed description, it 
may be well to state briefly a few facts as to the chemical composition 
of the body. 

The body of the cat is chemically composed of four principal 
elements, namely, oxygen, hydrogen, nitrogen, and carbon, with 
small quantities of other elements — sulphur, phosphorus, chlorine, 
fluorine, silicon, potassium, sodium, calcium, iron, and magnesium. 
These elements are united together so as to form water, carbonate 
of lime, chlorides of sodium and potassium, sulphates and carbonates 
of soda and potash, phosphates and carbonates of magnesia, fluoride 
of calcium, and ammonia, and they are ultimately united into very 
complex groups of elements, termed " organic " compounds, the 
study of which pertains to a special science called organic chemistry. 
These very complex chemical groups of elements are called the 
proximate elements of* the body because they are the first component 
substances into which it can be dissolved when in course of being 
reduced to its ultimate elements. Such proximate elements are 
grouped in two classes : 1. Those called nitrogenous, because con- 
taining nitrogen, and 2, the non-nitrogenous, because destitute of that 
element. Most of the component substances of the body, such, e.g., 
as the flesh and the blood, are composed of the first, or nitrogenous, 
proximate elements, of which the substance of the white of egg, 
called albumen, and that of jelly, called gelatine, form the types. 
Fats, on the contrary, are non-nitrogenous substances, and consist 
only of oxygen, hydrogen, and carbon, or if they contain other ele- 
ments, nitrogen is not amongst them. The nitrogenous substances 
are also spoken of as proteid, because they have been supposed to be 
derived from an imaginary substance termed protein, consisting of 
oxygen, hydrogen, nitrogen, and carbon. They are also spoken of 
as forms of protoplasm* About four-sevenths of the weight of the 

* A term proposed by Mohl to denote I creature is at first entirely composed of 
the soft interior of cells. Every living ' this quaternary compound. 



chap, i.] INTRODUCTORY. 13 

animal's body is made up by water, of which it is, therefore, very 
largely composed, the brain containing about seventy per cent, of 
that fluid. 

In saying that the body consists of different parts and substances, 
and is made up of combinations of elements, all that is meant is 
that it can be more or less readily divided into such parts, and that 
it can be dissolved into such elements, just as water may be destroyed 
to give place to oxygen and hydrogen. Whilst living, however, 
the body really forms one continuous whole locally differentiated, that 
is, assuming different appearances and possessing different properties 
in different regions. Even the very blood is directly continuous 
with the other constituents of the body in all actively growing parts. 



CHAPTER II. 

THE CATS GENERAL FORM. — THE SKIN AND ITS APPENDAGES. 

§ 1. The cat's entire frame is divisible into head, neck, trunk, tail, 
and limbs, of which latter there are two pairs. Its body is every- 
where more or less closely invested by a firm skin, nevertheless this 
is loosely attached in certain parts and so forms folds here and there, 
as e.g., between the trunk and the elbow and knee respectively. Its 
skin is almost entirely clothed with hair, which is generally of 
moderate length, often being longer on the belly and tail than else- 




Fig. 1.— Cat's Muzzle, showing Vibrissa and Naked Skin about the Nostrils. 



where ; but the length of the hair varies, as we have seen, according 
to the breed to which different cats may belong. It is, however, 
always short on the paws and face. The hairs are directed backwards 
from the head to the tail, and, for the most part, downwards on the 
limbs. There are long hairs inside each ear and sometimes on its tip, 
and about a dozen very long and strong hairs— the whiskers or 
vibrissa — are placed on each upper lip. There are also a few long 
hairs over each eye, or eyebrows, but there are no eyelashes. 
The end of the nose, the lips, and the skin of the fleshy pads 
beneath the paws, are naked. 



chap, ii.] TEE CAT'S GENERAL FORM. 15 

The head is rounded, and the jaws are rather short. The eyes 
are large, and separated by a considerable interval. The ears 
become narrow as they ascend, and each stands with its deep 
concavity directed forwards and outwards. The neck is a little 
shorter and less voluminous than the head. The front limbs are 
shorter than the hind limbs, and consist each of an upper arm, a 
fore-arm, and a paw with five short toes. Each hind limb has a 
thigh, a leg, and a foot with four toes. The proportions of the 
body are such that both the elbow and knee are placed close to 
the trunk. 

Certain symmetrical relations and contrasts between different parts 
of the cat's frame are evident on even a cursory examination of it. 
Thus there is an obvious contrast between its dorsal and its ventral 
aspect, and this contrast extends along each limb to the ends of the 
toes. 

Again, there is a resemblance (and at the same time a contrast) 
between the right and left sides, which correspond with tolerable 
exactitude one to the other. 

This harmony, termed bilateral symmetry, though obvious exter- 
nally, does not prevail in all the internal organs (viscera), which are 
more or less unsymmetrically disposed. 

Thirdly, there is a resemblance and correspondence between parts 
placed successively, as, for example, between the arm and the leg, 
or between the fore and hind paws ; although this resemblance 
is less obvious than it might be, owing to the different directions 
in which the knee and elbow are bent. Such a symmetry is termed 
serial, and is thus even externally visible ; but it becomes much 
more evident when the animal's internal structure is examined. 
There we find many successive parts — like the ribs, or the pieces of 
the backbone — which obviously resemble each other very closely, 
and so are called by a common name. Such parts are placed 
one after another in a " series," and it is on this account that the 
symmetry of which they are examples is called serial symmetry. 

If we remove the cat's skin we see beneath it a mass of red flesh. 
— the muscles or organs of movement — and these are divided one 
from another by delicate membranes. If the muscles be cut away, 
we come sooner or later to subjacent bones — those of the head, neck, 
trunk, tail or limbs, as the case may be. The bones of the head, 
trunk and tail, are the " skull, backbone and ribs." 

If the trunk be cut open, it will be seen that a variety of organs 
— heart, lungs, kidneys, stomach, intestines, liver, &c — lie enclosed 
in a cavity within it. If the skull and backbone be cut through, the 
white substance of the brain and spinal marrow will be found within 
them. Delicate threads of a similar white substance, the nerves, (which 
minister to motion and feeling) traverse the body in all directions, 
as also do a multitude of tubes or vessels, which convey blood to or 
from the heart. The anterior part of the trunk-cavity (which 
contains the heart and lungs,) is divided from the hinder portion by 
a fleshy and membranous partition — the diaphragm. This partition 



16 



THE CAT. 



[CHAP. II. 



is traversed by large blood-vessels and by the alimentary tube, wbich 
extends continuously from the mouth backwards to its posterior 
termination. The parts of which the cat's body are composed are 




Fig. 2.— Diagram representing a Vertical Section through the Oat's Body. 



n. Brain and spinal marrow contained within 
the skull and backbone, which are deep 
black. 

st. Breast-bone. 

dd. Alimentary canal. 

s. Stomach. 



h. Heart. 

cc. Great blood-vessels. 

u. Urinary bladder. 

sy. Chain of sympathetic ganglia. 

di. Diaphragm. 



thus conveniently divisible into the bones, with their membranes — 
the skeleton ; the muscles ; the nervous system and organs of sense ; 
the system of vessels, or circulatory system ; the alimentary tube, 
with its appendages ; the lungs and kidneys, with certain other 
parts, and the organs of reproduction. 



THE SKELETON. 

§ 2. The word " skeleton " is popularly taken to denote only the 
bones, with the cartilage or gristle which may be connected with 
them. It should, however, be taken to mean not only these but 
also the membranes, which radiating from the bones and cartilages 
invest every organ of the body, and finally clothe it externally in 
the form of " skin." Such membranes penetrate the very bones 
themselves and support the marrow they contain ; they separate 
every muscle from its neighbour, and surround and line each tube 
and passage in the body ; so that if every other tissue could be dis- 
solved away and yet this fibrous tissue be left, we should have 
a complete outline model, as it were, of the cat's entire frame. 

§ 3. This substance, which is, as it were, the basis of the skeleton, 
is formed of what is called connective tissue, which consists of a 
mass of delicate white fibres imbedded in a structureless material or 
" ground substance ; " scattered through this are minute particles of 
protoplasm, called " corpuscles," which are more or less rounded or 



CHAP. II.] 



THE CATS GENERAL FORM. 



17 



flattened in shape, sometimes giving off ramifying processes, which 
may unite with branches from neighbouring connective -tissue cor- 
puscles. Within the corpuscle is a round or oval nucleus, which 
contains one or more nucleoli* The structureless substance and 
fibres form what is called the matrix of the tissue, and the cor- 




Fig. 3.-- Connective, Adipose and Elastic Tissue. 



Loose areolar tissue -with fat cells. 

The fat cells. 

and C. Magnified view of areolar tissue 
treated with acetic acid. The white fibres 
are here no longer seen, and the yellow or 
elastic fibres with the nuclei come into 
view. In Fig. B, a series of constrictions 



is produced by the presence of an elastic 
fibre, which is spirally disposed about the 
(here swollen and invisible) white fibres. 
The white fibres may be 50000 0I " an incn in 
thickness or even less. 
Fibres of yellow or elastic tissue. 



puscles are cells which are thus more or less plentifully distributed 
within the matrix. 

Intermixed with the ordinary fibres may be others of a yellower 
colour (and with a different chemical reaction), known as " elastic 
fibres," or ''elastic tissue." These fibres may be rendered con- 
spicuous under the microscope by the addition of acetic acid, which 
causes the white fibres to swell and become indistinct, thus revealing 
the existence of the unaffected yellow ones. 



* It may be well to remind the reader 
that the body of every animal, and there- 
fore of the cat, consists at first of a single 
"cell," or minute particle of protoplasm, 
and afterwards, for a time, of an aggre- 
gation of such cells whence all the tissues 
of the body are ultimately derived, and 
which in different degrees preserve traces 
of their cellular origin. Cells commonly 



I contain a modified internal part or parts 
called a nucleus or nuclei, when they are 
said to be "nucleated." It is very 
common for the nucleus to again con- 
I tain a more minute internal particle, i 
| termed a "nucleolus," or it may have i 
several nucleoli. Thus, the connective- 
tissue corpuscles are "nucleated cells." 
C 



18 



THE CAT. 



[CHAP. II. 



Certain portions of connective tissue which connect adjacent bones 
or cartilages become very strong, and constitute the ligaments. 
These are flattened or rounded bands, formed of straight, parallel 
fibres and are very dense in structure, with corpuscles elongated in 
the direction of the fibres. 

Other fibrous structures are the membranes which closely invest 
the bones or cartilages, which membranes are called periosteum' and 
perichondrium respectively. These are formed of intersecting fibres, 
with blood-vessels, which latter are destined to supply the structures 
which the membranes invest. A more delicate connective tissue 
penetrates into the cavities of many bones, and is loaded with fat, 
forming what is known as marrow. Fat, or " adipose tissue," con- 
sists of round or oval vesicles (or minute bags), containing an oily 
matter. The vesicles are mostly from the T ^- th to the ^oVth of an 
inch in diameter. In the earliest period of its existence the 





a. Fibro-cartilage. 



Fig. 4. — Cat's Cartilage, greatly magnified. 
&. Hyaline cartilage, showing the nucleated cells enclosed in the capsules. 



skeleton consists entirely of connective tissue, but becomes largely 
transformed into bone — i.e., it ossifies — by the deposition of cal- 
careous salts around the blood-vessels, which advance and invade 
the tissue about to ossify. 

§ 4. Cartilage, is an opaque, firm but highly elastic substance, 
generally of a bluish- white colour. Like connective tissue it consists 
of a matrix, and this contains very distinct cells. The matrix, 
however, is generally homogeneous. Such is hyaline cartilage. Certain 
cartilage, however, contains fibres, and is therefore called fibro- 
cartilage, and if it contains elastic tissue also, it is known as yellow 
fibro-cartilage. The cells are inclosed, either singly or in groups, 
in rounded, unbranched hollows termed capsules, the walls of which 
may be somewhat denser than the rest of the matrix. Cartilage 



CHAP. II.] 



THE CATS GENERAL FORM. 



19 



does not contain blood-vessels, but can yet grow rapidly, the nuclei of 
the cells multiplying and the cells and corpuscles tbemselves enlarg- 
ing and dividing — the homogeneous matrix coming to occupy the 
intervening space as the capsules divide and separate. 

§ 5. Bone, or osseous tissue, is a substance, two-thirds of which, in 
the cat, consists of mineral matter — namely, of phosphate with 
some carbonate of lime, and a very little fluoride of calcium, phos- 
phate of magnesia and common salt. The animal * and mineral 
parts are absolutely united, since by the elimination of either, the 
shape of the bone remains unaltered. 

Compact bone, such as that which forms the thigh-bone of the 
cat, exhibits on its surface a number of microscopic holes, which are 
the external apertures of canals, called " Haversian,'* which thence 





Fig. 5.— Sections of Cat's Leo-bone, greatly kagnified. 



The right-hand figure shows the layers arranged 
concentrically around the Haversian canal 

The left-hand figure shows a section nearlv in 
the plane of such a canal. 



h. Haversian canal. 
I. Lacunae. 
c. Canaliculi. 



enter and ramify. These holes and canals serve to admit blood- 
vessels. The bony substance forms concentric layers about such 
canals, while the layers themselves contain a number of irregular 
radiating spots, which are also arranged in concentric rings corre- 
sponding with the layers in which they lie. These spots are inter- 
spaces called "lacunse," (and sometimes "bone corpuscles,") and 
their outline is so irregular because each gives off a number of 
minute tubular processes, termed canaliculi. The canaliculi of 



* This substance when boiled yields 
gelatine. Cartilage yields chondrin, 
which differs somewhat from gelatine in 
its chemical relations ; but, like it, dis- 
solves in hot water, and forms a jelly on 



cooling. Connective tissue also yields 
gelatine when boiled, but elastic tissue 
does not. The latter tissue is also (as 
before said) unaffected by acetic acid. 

o 2 



20 



THE CAT. 



[CHAP. II. 



adjacent lacunae unite, and thus fluid can traverse every part of 
the bone. 

The Haversian canals grow larger as they proceed inwards (in 
such a bone as that of the thigh,) and open into still larger channels 
and yet wider interspaces which are called cancelli, ultimately 
merging into a hollow central part called the medullary cavity of the 
bore because it contains that delicate fibrous tissue and fat which 
constitutes marrow, as already mentioned. 

Some bones have their entire substance replete with cavities or 
cancelli, and such are called cancellated or spongy. 

§ 6. Ossification may take place either through pre-existing carti- 
lage or through membrane, and in either case 
blood-vessels advance into the pre-existing ma- 
he terial, and therewith that material is absorbed 
and disappears around them and is replaced by 
calcareous substance. The lacunae are inter- 
spaces which have been left uncalcified owing 
to the presence there of certain cells. These 
cells have sent out radiating processes (like 
some of the connective-tissue cells, as already 
noticed,) which have also escaped the general 
calcification of the intercellular substance, and 
thus the canaliculi have been produced. Thus 
contents of the lacunae are truly bone- cells 
or corpuscles. Bone tissue therefore is, except 
as to its calcareous nature, very like connec- 
tive tissue and cartilage. The bony substance 
answers to the matrix of these other tissues, and 
the "bone cells" to their corpuscles. When 
the earthy matter of bone is dissolved their 
original cellular contents may often be detected. 
When a bone ossifies from cartilage, as all 
thick bones do, the deposit begins in the form 
of opaque granules of calcareous matter, which 
vertical Section of surround and sometimes invade the cartilage 
at's thighbone (Femur), capsules and form a dense and irregular osseous 
heTd ng of1h7t?r ( s 4 f Se tissue, without lacunas or canaliculi. Spaces are 
great trochanter (<e), and of then formed in this substance by absorption, 

its distal end (le). . . p , , . l A • 

and it these spaces JargeJy accumulate, can- 
cellated tissue is formed. The spaces may, 
however, become filled with a fresh and secondary deposit of bone 
in concentric rings round the blood-vessels, thus forming the 
" compact bone " already described. 

When bone is formed from membrane, it assumes the compact 
form, with lacunae and canaliculi, at once, and is not preceded by 
granular deposit. 

§ 7. The growth of bone takes place in various ways by the ossi- 
fication of the inner layer of the periosteum surrounding it. In long 
bones, which are preceded by cartilage, the ends remain for some 




Fig. 



Shown 



chap. ii. J THE CATS GENERAL FORM. 21 

time cartilaginous. These cartilaginous ends ossify subsequently,, 
but long continue distinct from the median part and are called 
epiphyses (Fig. 6), which only unite with the rest of the bone when 
the animal has attained maturity. Epiphyses are often developed 
at the ends of any projecting pieces of bone or " processes." 

A bone may thus be developed from more than one point, i. e., 
from several " centres of ossification, " the respective growths from 
which ultimately unite to form one whole. A continuation of the 
same process may fuse together even entire bones which have for a 
time remained separate and distinct. 

The most external layer of the skin consists of yet another 
substance, which is known as epithelial tissue, and which is very 
distinct in nature from connective tissue or the elastic cartilaginous 
or osseous modifications of connective tissue. 

§ 8. Such are the substances or tissues of which the cat's skeleton 
is in its entirety composed. 

That skeleton is naturally divisible into two parts : 

(a.) The external, peripheral skeleton, often called the Exo- 

skeleton — the skin and its appendages. 
(b.) The internal central skeleton, often termed the Endo- 

SKELETON. 

§ 9- The External Skeleton of the cat is made up of its skin, 
with the hair which coats it, the claws, and also the teeth. ]No 
cartilage or true bone enters into its composition. 

Tbe skin of the cat, like our own skin, consists of two layers : 
an external layer, devoid of nerves and blood-vessels (and conse- 
quently of feeling), and a deeper layer, which is supplied with both 
nerves and blood-vessels, and is highly sensitive. The external 
layer is called the epidermis, the deep layer is called the dermis. 
At the lips the external layer visibly changes in texture, and inside 
the lips and mouth it becomes soft and moist, and is termed mucous 
membrane. This, however, is a mere modified continuation of the 
external skin. The superficial layer of inwardly reflected skin is 
termed the epithelium, which is thus but a modified epidermis, and 
the common term Ecteron is applied to both epidermis and epithe- 
lium, as the term Enderon is applied to the deeper or dermal layer 
(i. e., the dermis) wherever situate. 

§ 10. The Epidermis is an epithelial tissue, and consists of 
numerous superimposed layers of epithelial cells, of which those near 
the surface are flattened into scales, while the deeper ones are more 
and more rounded, the deepest even assuming a vertically elongated 
form. As the epidermis is worn away from the surface in minute 
fragments, newer cells rise successively from below (to replace those 
lost) from a layer of structureless substance which connects the epi- 
dermis with the subjacent dermis. In this layer minute particles 
{nuclei) arise and gather round them spheroidal portions of the sub- 
stance itself, thus forming cells which subsequently multiply by spon- 
taneous division or fission, the process commencing with the division 
of the nucleus of each cell. The deeper strata of epidermis contain 



22 THE CAT [chap. ii. 

the colouring matter of the skin, and are often considered as forming 
a distinct part called the rete mucosum. The superficial or older 
layers acquire a horny nature. The surface of the epidermis ex- 
hibits numerous minute orifices of sweat-glands — the pores— and, 
especially on the paws, numerous minute ridges. 

§ 11. The dermis, or corium, is a form of connective tissue. Its 
upper surface is almost free from fibres, but beneath, these first grow 
abundant and then begin to leave larger and larger interspaces, till 
the fibrous tissue becomes what is called " areolar" and so forms the 
substance connecting the skin with the subjacent structures, i.e., it 
forms that white, filmy substance which is broken through when the 
animal is skinned. In the deeper portion of the true skin there are 
curled yellow fibres of elastic tissue, and there may be some or many 
muscular fibres. Its outer surface is drawn out into little promi- 
nences or papillae arranged in close-set parallel rows (especially on 
the paws), which occasion the ridges above mentioned, or existing in 
the superimposed epidermis. Many of these papillae contain nerves 
and blood-vessels, the former ending in a fine coil about a minute 
ball or core of nucleated tissue, thus forming what are called " axile 
bodies," or "touch corpuscles " (Fig. 7, B). 

Sweat-glands consist of minute tubes, each opening at the surface 
at a " pore," whence it descends into the skin and passes through it 
into the loose connective or areolar tissue beneath it, where it ends 
in a coil surrounded by minute blood-vessels. The meshes of the 
loose subcutaneous tissue contain fat, which, as before mentioned, is 
enclosed in minute bags of membrane. It is fluid during the life of 
the animal, and both helps to keep the body warm (being a bad 
conductor of heat) and serves as a store of nutriment. Other 
structures called Pacinian bodies are found in some parts of the skin 
of the body — notably in a membrane (the mesentery) which invests 
part of the bowels. Each such body consists of a number of layers 
of membrane, with fluid interposed, and with a central space into 
which a nerve enters (Fig. 7, A). 

§ 12. The claws, of which there are five to each fore-paw, and four 
to each hind-paw, are special thickenings of epidermis, and are 
(like the outer layer of epidermis generally) horny. But the dermis 
is also specially modified with a view to the formation of the claws ; 
for at the root of each claw it forms a transverse crescentic fold over it, 
while beneath the claw, it is produced into a number of close-set rows 
of papillae richly supplied with blood-vessels — forming what is called 
the matrix of the claw. From its surface, and also within the 
crescentic fold, fresh epidermal cells are continually formed, which 
rapidly become harder, and cohere to form the claw, the root part 
of which is soft, like the deeper layer of epidermis, with which 
layer it is directly continuous. The claws are placed around the 
terminal part of the last bone of each toe, completely investing it, 
and ending in a sharp point. 

§ 13. The hairs each consist of a root, fixed in the skin, and the 
shaft, or stem, which may be cylindrical, or flattened. Each hair is 



CHAP. II.] 



TEE CATS GENERAL FORM. 



23 



formed, like each claw, of modified epidermal cells, but then each hair 
grows from a single dermal papilla only, of which it is the greatly 
prolonged epidermal covering. Moreover, this dermal papilla does 
not stand up from the surface of the dermis, but is placed at the 




Fig, r. 



A. Pacinian Body from Cat's Mesentery. 

a. Artery. 
n. Nerve. 
/ Fibrous tissue. 



B. TOUCH-CORPCSCLE. 

ca. Epithelium. 

c. Nuclei. 

n. Core, into which the nerve enters. 



bottom of a small sac, the follicle, which is a depression in the 
cutis. The central part of the hair, or pith, is less dense than its 
rind, or cortical substance, wnich is formed of very long, horny cells 
which have coalesced. Outermost of all is the cuticle or epithelial 
layer, formed of very thin overlapping scales. The colouring 
matter is deposited within the outermost layer, and may be uniform 
throughout, or may be different in different parts of the same hair. 
Some hairs are especially slender, and have the edges of the scales 
of their cuticle so projecting, as to form a serrated envelope. Such 
hairs are " wool," and easily become entangled and adherent to- 
gether by their serrations, or " felted." True hair, such as the cat's, 
has not the property of "felting," because its surface is smooth. 

Although hairs (like claws, and the epidermis generally) have 
no blood-vessels, yet the sudden changes which may sometimes take 
place in their colour, prove that nutritive modifications extend into 
them. 

Very small vessels pass into the papillae of the hairs, which are 
also furnished with a minute nerve, to the presence of which 
the pain felt when the hair is pulled out is due. 



24 



THE CAT. 



[CHAP. II. 



The root, or bulb, of each hair consists of the dermal sac with its 
enclosed papilla and the epidermal formation which lines the sac 
and invests the papilla. It is considerably larger than the diameter 
of the hair it developes. 

The cat's whiskers are simply hairs of great size, the bulbs of 
which are well furnished with blood-vessels and nerves. 

Hairs are inserted obliquely into the skin, but can be made to 
stand up, or "on end" — as notably on the cat's tail when the 
animal is enraged — by means of the contraction of small muscular 
fibres which pass from the skin to the hair-bulbs. 




Fig. 8.— Transverse Section of a Cat's 
e. Cortical substance. 



GREATLY MAGNIFIED. 

m. Pith or medulla. 



Certain accessory structures are called sebaceous glands. These 
are minute flask-shaped bags (secreting an oily substance), which 
open into the upper part of the hair follicles, and so serve to 
lubricate the hair. 

New hairs are formed by the budding off of a new papilla and 
follicle from beside tho&3 first developed, and by the growth of a 
cluster of epidermic cells at the bottom of the new follicle. Neither 
the new nor the older follicles are really formed by an actual in- 
flection of the skin, though when completed they appear as if they 
had been so formed. Minute blood-vessels and nerves enter the roots 
of hairs, but do not extend beyond the dermal papilla. 

§ 14. Such are the appendages and such is the nature ot the skin 
which clothes the cat's body externally, and which varies in thickness 
in different regions, being very thin on the lips, ears, and eyelids, 
thicker on the back and outer sides of the limbs than on the belly, 
and especially thick upon the pads of the feet on which the animal 
walks. Of these there are seven in the fore paw, and five in the 



CHAP. II.] 



THE CATS GENERAL FOBM. 



25 



hind paw. Each pad consists of a mass of fibrous tissue and fat, 
and a large trilobed one is placed beneath the ends of those bones on 
which the animal rests in walking, as represented in the figure here 




w 



nr 



iy^''"'A 



Fig. 9. — Under. Surface of Fore-paw. 

I, II, III, IV, V. The five toes, I being the 

pollex. 
a. Trilobed pad which lies beneath the distal 

ends of the metacarpal bones. 
* Pad beneath the pisiform bone of the wrist. 





Fig. 11.— Columnar ciliated Epithblial 
Cells, magnified 300 diameters. 

A number of cilia are seen on the flattened 
superficial end of each cell, which also con- 
tains a nucleus with a nucleolus. 



Fig. 10.— Under Surface of Hind-paw. 

II, III, IV, and V. The respective four digits. 
a. Pad beneath the metatarsal bones. 
h. Heel. 



given. But, as before observed, the skin does not clothe the exterior 
of its body only ; at the margin of the lips it is reflected inwards, 
lining the mouth and continuing onto line the whole alimentary canal, 
and it also lines all the other passages which open on the exterior of 
the body. The cat's body may thus be compared with a ring-shaped 
air-cushion which has been very much drawn out on each surface, 
the central vacant space being also greatly prolonged, but contracted 
in diameter to represent the alimentary canal. 



26 



THE CAT. 



[CHAP II. 



Thus the real body of the animal lies enclosed between the external 
skin and its internal reflected continuation, and answers to the en- 
closed interior of the ring- like air-cushion. A real " body cavity " is 
therefore not the inside of the alimentary canal, or the inside of any 
other passage opening on the exterior ; all such passages being of 
course but so many continuations inwards of external space. A real 
" body cavity " would be any cavity existing enclosed between the 
external skin and its internal reflected continuation. This reflected 
skin is soft and delicate, with a moistened surface, and is called 
" mucous membrane." Such membrane lines two great sets of 
organs. One of these is the gastro-pulmonary mucous membrane, 
and lines the mouth and alimentary canal, the eyelids, ears, nostrils, 
cavities in the skull, and the windpipe and lungs. The other is 
called the gerito-urinary , and lines the bladder and the parts con- 
nected with its passage outwards. 

§ 15. Just as the external skin consists of epidermis and dermis, so 
its reflected portion consists of a n on- vascular epithelium, with a sub- 
jacent highly vascular corium, which often contains much muscular 
fibre. Between them is the homogeneous structureless layer termed 
the basement membrane. The component cells of the epithelium 
may be elongated at right angles to the basement membrane, thus 
forming what is called " columnar epithelium " (as in the stomach and 
intestine), or they may be rounded, forming spheroidal epithelium, as 
in the lining of the ducts of the " glands " * of the alimentary canal. 

Sometimes parts of the substance of epithelial cells may protrude 
as thread-like processes or cilia, which are capable of performing 
repeatedly a whipping-like movement. A membrane consisting of 
such cells is called ciliated epithelium (Fig. 11), and such we shall find 
in certain of the cat's alimentary and respiratory organs, in the 
description of which f this kind of tissue will be again noticed. 

The corium contains yellow (or elastic) as well as white fibres, 
and the supply of either may be copious or scanty. Its surface may 
be even or very uneven. Thus it may be produced into many, 
often relatively large, papillae or villi — scattered or closely set — or 
into ridges which may so intersect as to form polygonal pits between 
them. 

Just as the outer skin is furnished with sweat and sebaceous 
glands, so also mucous membrane is copiously furnished with small 
glands which have different functions in different parts ; but a generally 
diffused secretion, called mucus, is formed by them, which gives its 
name to the membrane in which its formative glands are imbedded. 
It is slightly alkaline, and serves to preserve the moisture of the 
surfaces it lubricates, as well as to protect them from the dissolving 
action of fluids secreted to dissolve and digest food temporarily held 
within cavities (the stomach &c.) which are lined by mucous 
membrane. 



* Epithelial cells may, as we shal 
hereafter see, take on the function 
manufacturing some special product 



"secretion." Parts which thus act are 
termed "glands." 

t See below, Chapter VI. 



CHAP. II.] 



THE CAT'S GENERAL FORM. 



£7 



The mucous membrane is connected with the subjacent parts by 
submucous areolar tissue, which is often lax, so that the mucous 
membrane, when not stretched, is thrown into effaceable fold's or 
rugce. It may also form folds which are not to be effaced by any 
stretching of the skin, as, e.g., on the palate (Fig. 86). 

The membrane lining the mouth abounds in small glands, 
those within the cheeks and lips being termed buccal and labial 
respectively. 

§ 16. The mucous membrane of the mouth has certain calcareous 
appendages— the teeth — which are mainly calcifications of the 
corium, but in part are ecteronic — or calcifications of the epithelium 
— so that the nature of each is compound. 

The teeth are not only parts of the external skeleton, but are 




Fig. 12.— The Teeth of the Right Side of a Cat's Mouth, seen on thetr Tnner Surfaces. 



Incisors. 
. Canines. 
pm. Premolars. 



m. Two molars. (The outer aspect of the teeth 
is shown in Fig. 46. See also Fig. 29.) 



closely related to the internal skeleton also, since they are implanted 
in special sockets — or alveoli — provided for them in the margins of 
the jawbones, which margins are on that account spoken of as 
" alveolar." The part of each tooth which is thus implanted is its 
"fang." The part which appears above the surface of the mucous 
membrane is called the " crown," and the line of junction is the 
cervix, or neck. Each alveolus closely invests the fang contained 
within it. Most of the teeth have but a single fang, which tapers 
as it penetrates its alveolus ; but there may be two or three fangs to 
a single tooth. 

The teeth of the cat, when adult, should be thirty in number. 
Those of the two bides of each jaw are alike, but those of the upper 
jaw differ from those of the lower jaw. 

The three front teeth of each lateral half of the upper jaw are 
very small and simple in shape. They stand side by side, so that 



28 THE CAT, [chap. u. 

they form (with their three fellows of the opposite side) a row of six 
teeth arranged in the same transverse line. Each tooth has a single, 
conical fang. The first, or innermost — of the three teeth of this 
kind on each side — is the smallest, and the outermost considerably 
the largest. The innermost, when quite unworn, has its crown 
indented by a transverse furrow, while the part anterior to the 
furrow is produced into three points or cusps, whereof the middle 
one is the largest. The next tooth is similar, save that the outer- 
most of the three cusps is larger and the innermost one smaller 
than in the tooth first described. In the third tooth there is no 
innermost cusp, and the outer one is much smaller, while the inner 
one (corresponding with the middle cusp of the two preceding 
teeth) is very much larger, forming almost all the crown of the 
tooth. This is the condition of these teeth only when quite unworn ; 
very soon there can only be distinguished a slight transverse pos- 
teriorly placed furrow, with a prominence in front of it, which is 
more or less irregular in outline. These three teeth are called 
incisors, and thus there are altogether six incisors in the upper jaw. 

The next tooth, which is separated from the outermost incisor by a 
considerable interval or diastema, is a very large, strong conical tooth 
called a canine, with a fang generally much thicker and larger than 
its crown. The crown is somewhat curved, and is sharply pointed 
with a strongly marked vertical groove on its outer surface, and a 
less marked groove on the surface which is turned towards the inside 
of the mouth. On its hinder margin is a more or less distinct 
vertical ridge. 

The next tooth (separated from the canine by an interspace) is a 
very small one, and, like the two which come behind it, is called 
a premolar. It has an obtuse conical crown with a single fang. 

The next tooth, or second premolar, is very much larger, and has 
two diverging fangs, one in front of the other. Its crown is com- 
pressed or flattened from within outwards, and consists of one large 
triangular pointed cusp, at the base of which there is in front a 
small single tubercle, while, posteriorly, there are two small ones 
juxtaposed, one behind the other. The third premolar is yet larger 
-^the largest of all the cat's teeth— and from its trenchant shape (so 
well adapted to cut flesh) is called the upper sectorial tooth. It has 
three fangs, two smaller in front (placed one within the other on the 
same transverse line) and one much larger, placed posteriorly. 

Its crown consists of three external lobes (or cusps), separated by 
two notches, and of one internal tubercle. Of the external cusps 
the first is the smallest, and the second, which is backwardly 
directed, is the largest. A ridge from the first and second extends 
inwards to meet at the internal tubercle (Fig. 29), which projects 
downwards but little. A very slight horizontal prominence or 
ridge (the external cinguhm) connects the bases of the three external 
cusps on the outer surface of the tooth. When this tooth is viewed 
from within, a sharp ridge is seen to connect the middle and hind- 
most of the external lobes, forming a very cutting blade, deeply 



chap, ii.] THE CATS GENERAL FORM. 29 

notched at its middle. Behind the third premolar is an exceedingly 
small tooth, which is called a true molar. It has two small fangs 
and a flattened crown, the greatest "breadth of which (Fig. 86) is 
from without inwards. The common term molars is often used to 
denote all the teeth which are neither incisors nor canines ; it being 
sometimes convenient to speak of such teeth as one whole, without 
distinguishing between premolars and true molars. In the lower 
jaw, at its anterior end, there is also a transverse row of six small 
incisors. The three of each half of the jaw increase in size from 
within outwards, as do those of the upper jaw; but they are all smaller 
than the upper incisors, especially the third, or posterior, one, which is 
not conical, like the corresponding tooth above. Then comes, with- 
out any interspace, a large, strorg, pointed canine, so placed as (when 
the jaws are closed) to bite in 4 Vont of the upper canine, passing up 
in the interspace between the upper incisors and canines. The lower 
canine resembles the upper canine in shape, save that it is somewhat 
shorter and more curved — its anterior and posterior margins being 
rather strongly convex and concave respectively, Next to the lower 
canine follow two premolars and one molar, separated however from 
the canine by a wide diastema. The first premolar corresponds with 
the second upper premolar, and bites in front of the latter. It has 
two fangs, while its crown (like that of its analogue above) has one 
large central lobe, at the base of which are two small cusps behind, 
with one in front. 

The second premolar has also two fangs, and is like its pre- 
decessor, save that it is larger. The lower molar is very unlike 
the upper one, having a more completely trenchant form than any 
other tooth. It is called the lower sectorial tooth. It has two 
fangs, whereof the anterior is much the larger. Its crown consists 
of two nearly equal lobes, each ending in a point, the points di- 
verging. At the base of the hinder side of the hinder lobe there is 
a minute, scarcely perceptible, indication of a posterior tubercle or 
"talon." On its inner side, the crown is deeply excavated between 
the lobes ; but externally the surface is equably convex, save that 
a fissure descends vertically from the apex of the notch dividing the 
two lobes. The adjacent edges of each lobe are very sharp, so that 
the tooth presents an exceedingly trenchant margin, which bites 
against the similarly trenchant cutting edge above described as 
connecting the middle and hindmost external lobes of the upper 
sectorial. Thus these two trenchant margins act together like two 
blades of a pair of ivory scissors. 

§ 17. The teeth of the adult cat are preceded by a somewhat 
different set, forming its milk-teeth or deciduous dentition. There 
are on each side of the upper jaw three deciduous incisors, one 
deciduous canine and three deciduous molars, and the same on each 
side of the lower jaw, save that there is one deciduous molar less. 
There are thus twenty-six milk-teeth in all. The deciduous incisors 
appear when the kitten is between two and three weeks old, then 
follow the canines and molars, all appearing by the end of the sixth 



30 



THE CAT. 



[CHAP. II. 




week. They begin to fall out after the seventh month, hut the 
lower true molar comes into its place before the deciduous molars 
fall out. In shape the upper incisors are like their permanent 
successors, save that the transverse furrow is less marked. The upper 
canines are smaller and less grooved than the permanent ones. 
The first upper deciduous molar is a small, simple one-fanged 

tooth like its vertical suc- 
cessor. The second de- 
ciduous molar is quite 
unlike the tooth which 
replaces it, but nearly 
resembles the third 
upper premolar or sec- 
torial. Its outer cutting 
part, or blade, is three- 
lobed, but both the an- 
terior and posterior lobes 
are notched, and the in- 
ternal tubercle, which is 
relatively larger than in 
the permanent sectorial, 
is continued from the 

Fig. 13.- The Cat's Milk Dentition, enlarged. bage of the m [^\ e lobe# 

There are three fangs, 
but the inner fang is 
more opposite the inter- 
space between the two 
outer fangs than is the case in the true or permanent sectorial. 

The third upper deciduous molar is again quite different from the 
tooth which succeeds it, while it resembles the true or tubercular 
molar of the upper jaw, save that its relative size is larger. 

The first deciduous lower molar is like the second premolar, while 
the second deciduous molar is like the inferior sectorial, with a 
relatively smaller anterior lobe and a much larger posterior tubercle, 
or talon, which is notched so as to form two smail posterior tubercles 
at the base behind the posterior and greater lobe, 

§ 18. Such being the dentition (i.e. tooth-furniture) of the cat, it 
may be conveniently expressed by the following symbols : — 

i-J c-f- FMf M-j- for the second, or permanent dentition. if 
means " three incisors, above and below, on each side of the jaws ; " 
c T means similarly, " one canine on each side of each jaw ; " pm-| 
means "three premolars on each side of the upper jaw and two on 
each side of the lower jaw ; " and m-j- means " one true molar both 
above and below on each side." Similarly, the symbols Dif, dc-J, 
dm|- for the milk dentition, refer in the same manner to the 
deciduous incisors, canines, and molars respectively. 

It need hardly be added that each tooth attains its full develop- 
ment within a limited time, after which it grows no more, and no 
third development ever replaces the fall of a tooth of the permanent 
dentition. 



Below, the true molar is seen much advanced, and soon 
to rise behind the second lower deciduous molar. In 
the upper jaw the permanent upper sectorial is seen 
in an advanced state of development above the third 
deciduous molar. 



CHAP. II.] 



TBE CATS GENERAL FORM. 



31 



§ 19. The substance of each, tooth consists of a dense tissue of three 
kinds, called (1) Dentine, (2) Enamel, and (3) Cement, investing a 
small soft and sensitive mass called the pulp. The great body of 
each tooth is formed of dentine, and it is this which immediately 
surrounds the pulp. The cement coats the fang of each tooth only, 
while its crown is invested with a covering of enamel, which is the 
hardest kind of tooth substance. 

The pulp consists of areolar tissue with cells and nuclei, and is in 
fact a modified portion of the corium — a large dermal papilla. It is 
highly vascular, and supplied with a nerve also. 

Dentine is an animal substance impregnated with 72 per cent, of 
earthy matter, of which nearly 67 per cent, is phosphate of lime. 





Fig. 14 —Tooth Substances. 



A Vertical section of second upper premolar. 
B. Horizontal section of right upper sectorial. 



d. Dentine, c. Cement, e. Enamel. 
pc. Pulp cavity. 



Instead, however, of presenting the lacunae and canaliculi of ordinary 
osseous tissue, dentine only exhibits a number (but an enormous 
number) of very minute and very close- set tubes, which radiate 
from the wall of the pulp cavity on every side and with slight 
undulations ; they become smaller towards the outer part of each 
tooth, while at their inner ends their diameter is about the 43V0 of 
an inch. Each tube, as it proceeds, gives off exceedingly minute 
branches, which appear to anastomose, and the tubules end distally 
by forming loops or by opening into minute cavities (dentinal cells) 
which are disposed around the dentine close to its surface, forming 
what is called its granular layer. 

The greater part of the earthy matter is contained in the matrix, 
between the tubules, which do not in fact proceed from the pulp, 
but advance upon it, the outermost layer being that first calcified. 

The Cement closely resembles bone, since it contains both lacunas 



32 



THE CAT. 



[chap. II. 



and canaliculi. It is thinnest towards the cervix of each tooth, and 
thickens towards the apex of each fang, and there it may even 
contain vascular canals like the Haversian canals of bone tissue.* 

The Enamel is so mineralized a structure that it only contains 
about 3 J per cent, of animal matter, while it has 90 per cent, of 
phosphate of lime. It consists of a multitude of slender, solid, 
undulating, hexagonal rods, closely adjusted to each other, and 
about 5 oV of an inch in diameter. Each rod is attached by one 
end to a minute depression of the surface of the aentine, and thence 

extends outwards, its distal part being 
at right angles to the external surface 
of the enamel. 

§ 20. We have seen that hair and claws 
are epidermic dermal appendages, but 
teeth are appendages of the dermis. They 
are not altogether so, however; for though 
the dentine is formed by ossification of a 
process of the corium, and cement by calcifi- 
cation of the connective tissue surrounding 
that papilla, yet the enamel has a different, 
and indeed an epidermal origin. It is formed 
from a depression of the epithelium of the 
gum, which dips in till it becomes applied 
to the apex of the rising dermal papilla, 
which last is destined, by its calcification, 
to form the bulk of the tooth. Having 
thus applied itself to invest the crown of 
the nascent tooth, it calcifies and so be- 
comes the enamel. 

Thus each tooth has a double nature. By 
its dentine and cement it is dermal, but 
its enamel is a modification of the epi- 
dermis. 

Each permanent tooth takes its origin 
in a cavity of the jaw, placed just behind 
the milk-tooth it is destined to succeed. 
A little process from the inflected epi- 
thelium (or " enamel organ ") which 
forms the enamel of the milk-tooth, is 
given off to invest the minute papilla 
which is to grow into the permanent tooth. 
As the new tooth is formed it rises in the gum, the space inter- 
vening between it and its successor becoming richly supplied with 
blood-vessels. The substance of the milk-tooth then becomes 




Fig. 15.— Thin Section of the 
Enamel and a part of the 

])ENTINE, 300 DIAMETERS. 

a. External surface. 

b. The rods or solid, six-sided 

prisms. 
d. Tubuli of the dentine. 

c. Clefts which occasionally 

exist in the deep part 
of the enamel. 



* A substance called osteo-dentine is 
sometimes produced by the ossification 
of the pulp itself. It has vascular quasi 
Haversian canals, surrounded by con- 



centric lamellre, and is so far like bone. 
On the other hand, tubuli radiate from 
these canals, which tubuli are larger 
than the canaliculi of bone. 



chap, n.] THE CAT'S GENERAL FORM. 33 

rapidly absorbed away by the aid of the blood-vessels — first the 
cement, then the dentine, and even part of the enamel — till what is 
left becomes loosened and falls out. As the new tooth rises into the 
place of its predecessor, the bone of the jaw becomes simultaneously 
modified by absorption and redeposition, so as accurately to fit its 
fang — a striking example of that wonderful power of harmonious 
and spontaneous modification which pervades the living body. 



CHAPTER III 

THE SKELETON OF THE HEAD AND TRUNK. 

§ 1. The internal skeleton, or endoskeleton, of the cat is made up 
of numerous bones with cartilages and fibrous structures. 

The number and nature of the parts vary with age. In the 
earlier stages of existence the cat has no bones at all, but ossification 
having once begun, goes on for a time energetically till maturity is 
attained ; and, indeed, to a certain extent ossification goes on 
throughout life. 

In this way it comes about that parts which are membranous in 
the kitten, or cartilaginous in the young cat, become bony in the 
full-grown animal. A continuation of the same process tends 
to unite bones which at their first appearance were separate. 
This process of union of bone with bone is called anchylosis. The 
hard parts of the internal skeleton being those which act as a 
framework support the body, form points of attachment for the 
muscles which move it ; the muscles employing the different bones 
like so many levers or fulcra, as the case may be. 

The great majority of bones being thus intended to move one 
upon another, certain parts of their surfaces are specially modified 
for mutual adjustment and motion, i.e. the contiguous surfaces of 
such movable bones form joints. 

These modifications will appear, as the forms of the bones are 
successively noticed ; but the nature and mechanism of all the 
different kinds of joint will be more conveniently considered together 
after the skeleton has been described, immediately before studying 
the m oving organs themselves. 

§ 2. The parts which compose the internal skeleton may obviously 
be grouped into two divisions : — 

(a). The skeleton of the head, trunk, and tail, which is called 
the axial skeleton. 

(b). The skeleton of the limbs, which is called the appendi- 
cular skeleton, the limbs being regarded as appendages of 
the axial part of the body. 

THE AXIAL SKELETON. 

The axial skeleton is further conveniently divisible into the 
skeleton of the back, or spinal skeleton, — consisting of what is 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 35 

familiarly known as the backbone, ribs and breastbone — and the 
skeleton of the head, or cranial skeleton. 



THE SPINAL SKELETON. 

As has been said, this consists of the backbone, together with certain 
arches, the ribs, which extend from each side of a certain portion of 
the backbone downwards to or towards the breastbone or sternum. 

§ 3. The backbone, or, as it is often called, the spine or spinal 
column, consists of a number of small bones placed one behind the 
other, like a series of counters. Each of these small bones is called 
a vertebra, and (with certain few exceptions, to be considered 
later) consists of a bony arch projecting upwards from a solid disk — 
the counter-like portion of the bone. Each whole vertebra may 
thus be described as a ring much expanded at one part, which is 
the lower part, and with certain bony prominences, which stand out 
from the bony ring in various directions. 

The vertebrae being, as has been said, placed one behind or in 
front of the other, their juxtaposed rings together form a long 
horizontal canal (ring being placed opposite ring), which is called 
the vertebral canal. It is also called the neural canal, because it is 
destined to contain and protect the central part of the nervous 
system of the trunk, namely the spinal cord — or, as it is popularlv 
termed, the spinal marrow. 

The thickened inferior parts of the vertebrae are also adjusted one 
in front of another, and by their juxtaposition form a solid but 
flexible horizontal rod. 

§ 4. The thickened inferior part of each vertebra is called its 
"body," or centrum (see Fig. 16) ; the ring of the vertebra springing 
from the centrum is called, as before said, the neural arch. Each 
lateral half of the neural arch consists of two parts : an inferior 
rounded part called the pedicle, and a superior broad and flat 
portion called the neural lamina. 

The various bony prominences of the vertebrae are termed 
"processes," and at least three kinds of such processes are very 
generally present. 

The first of these is the process which projects upwards from the 
junction of the neural laminae at the summit of the neural arch. 
This is the spinous process, neural spine, or neur apophysis. From the 
junction of each lamina with its pedicle another process, ending 
bluntly, juts outwards and upwards : this is called the transverse 
process. Other processes which project more or less forwards and 
backwards from the outer part of each lamina to meet corresponding 
processes of adjacent vertebrae, are termed articular processes or 
zygapophyses. 

Those projecting forwards have a smooth articular surface, which 
looks mainly upwards, and are called anterior articular processes, or 
vrezygqpophyses. 

d 2 



36 THE CAT. [chap. hi. 

Those projecting backwards have a smooth articular surface, which 
looks mainly downwards, and are called posterior articular processes, 
or postzygapophyses. 

The anterior margin of each pedicle is somewhat concave, while 
its posterior margin is generally more so. In this way, the vertebrae 
being naturally juxtaposed, the adjoined concavities, or notches, of 
two adj?°,ent vertebrae, constitute a rounded opening termed an 
intervertebral foramen. These foramina communicate with the 
neural canal, and enable nerves and vessels to pass thence outwards. 

The adjacent surfaces of the bodies of the vertebrae are nearly 
flat, and are connected together by the intervention of a fibrous pad 
— the intervertebral substance— which will be described later, 
amongst the ligaments. 

The vertebrae are composed of cancellous bony tissue invested by 
compact bone. The latter is most abundant on the arch and 
processes. The body of each vertebra is almost entirely composed 
of spongy substance traversed by canals for veins. 

Such is the general condition of most of the vertebrae, but in 
some of them certain of their parts and processes are wanting, while 
in others there are additional parts and processes. 

§ 5. The vertebrae are divisible into five different categories. (See 
Fig. 23, c, d, I, s, and cd). 

First come those of the neck, which are termed cervical. They 
are seven in number. 

Secondly, those of the back, which have the ribs attached to them 
and are called dorsal. Of these there are thirteen. 

Thirdly, we find certain large vertebrae which do not bear ribs : 
these are situate behind the dorsal vertebrae and are called lumbar. 
There are seven of them. 

All the above are termed " true vertebrae," because they do not 
become anchylosed together, but remain connected only by ligaments 
and by the intervertebral substances. 

Behind these true vertebrae come three which are called " false," 
and which sooner or later anchylose together to form a bony mass. 

This mass, termed the sacrum, comes immediately behind the 
lumbar vertebrae, and part of it affords attachment on each side to 
one of the haunch, or hip, bones. The sacral vertebrae thus anchy- 
lose together to constitute the sacrum. The rest of the vertebrae are 
called caudal, and form a series of some twenty bones which decrease, 
gradually, backwards as regards their complexity of structure, but 
increase in length to about the tenth, and then again become 
successively shorter, as well as simpler, to the end of the tail. 

§ 6. Of the vertebrae, the dorsal, as the simplest of those in 
front of the tail, may first be selected for description, the fifth 
dorsal being taken as the type. The centrum of this vertebra (c) 
is about three quarters as deep from above downwards as it is 
broad from side to side, its length (from before backwards) being 
about equal to its breadth. Its upper surface is more or less flat- 
tened. Its under surface is strongly convex from side to side, 



chap, in.] SKELETON OF TEE READ AND TRUNK. 



37 



and somewhat concave from before backwards. Its anterior and 
posterior surfaces are flattened, but the former is somewhat convex 
and the latter somewhat concave. The pedicles have their anterior 
notches very shallow, but their posterior ones very deep. The 
neural laminae are almost as wide from before backwards as from 
side to side, and the neural arch overlaps that of the vertebra 





Fig. 16. — Fifth Dorsal Vertebra. 



A. The vertebra seen on its right side. 

B. Anterior view. 

C. Posterior view. 
6. Small tubercle. 

c. Centrum. 

d. Tubercular surface. 



p. Capitular surfaces, 
s. Neural spine. 
t. Transverse process. 
Z. Anterior zygapophysis. 
3. Posterior zygapophysis. 



next behind. The spinous process is very elongated, pointed and 
inclined upwards and backwards. The zygapophyses are almost 
horizontal, the anterior ones (Z) looking upwards and slightly 
forwards and outwards ; the posterior ones (3) looking downwards 
and slightly backwards and inwards. 

The transverse process (t) projects outwards from nearly the 
summit of each pedicle, almost entirely hiding the anterior zyg- 
apophyses when the vertebra is seen in profile. A little tubercle {b) 
projects from the upper surface of the distal part of the transverse 
process.* 

Like almost all the other dorsal vertebrae, the fifth dorsal exhibits 
certain articular surfaces which are called costal, because they serve 
for the attachments of the ribs. There are two kinds of such 
surfaces. One kind, attached to the centrum, are called capitular, 
because they articulate with the heads, or the capitula, of the ribs. 
The other kind, attached to the transverse processes, are called 

* "Distal" and " proximal " are two 1 distal part of a limb ; that part of a liinb 

words respectively expressing remoteness which joins the body is the proximal 

from and nearness to a centre or point of part. The tip of the tail is " distal ; " 

attachment. Thus, e.g. the paw is the | its root is "proximal." 



38 THE CAT. [chap. hi. 

tubercular, because they articulate with the tubercles of the ribs. 
The tubercular surface (d) is a smooth, oval surface, slightly pro- 
longed from before backwards, and placed one beneath the distal 
end of each transverse process and giving attachment to the tubercle 
of the fifth rib. 

The capitular surfaces (p, p) are two in number on each side. 
One is placed at the junction of the pedicle with the centrum in 
front ; it is smooth, and looks forwards and outwards. The other 
is placed just beneath the posterior notch of the pedicle ; it is 
smooth, and looks so almost directly backwards and so very little 
outwards as to form part (the outer and upper angle) of the posterior 
surface of the centrum. The anterior capitular surface concurs with 
the posterior capitular surface of the fourth vertebra to form with it 
an articular cavity for the head of the fifth rib. Similarly its 
posterior capitular surface concurs with the anterior capitular surface 
of the sixth vertebra to form an articular cavity for the head of the 
sixth rib. 

The ring formed by the neural arch and centrum is oval, trans- 
versely extended, and somewhat flattened below, 

The eleventh, twelfth and thirteenth dorsal vertebrae have each but 
a single capitular surface on each side — namely, an anterior one. 
The first dorsal has an anterior capitular surface large enough to 
receive the whole head of the first rib. The eleventh, twelfth and 
thirteenth vertebrae have no tubercular surface. 

The first two dorsal vertebrae have the front surface of the centrum 
strongly convex and looking much downwards, and its hinder surface 
concave and looking much upwards. The tubercular surface also is 
strongly concave. 

As we proceed from before backwards, through the series of dorsal 
vertebrae to the tenth, the transverse processes come to extend less 
outwards and to be more expanded from before backwards at their 
distal ends ; the postzygapophyses become situated further backwards, 
and the neural spines (counting, at least, from the seventh,) also 
become shorter. 

The tenth dorsal vertebra has its transverse process very much 
extended from before backwards (Fig. 1 7, 10 ). Its posterior end projects 
backwards more than in any preceding vertebra, reaching to, or 
even beyond, the anterior margin of the pedicle of the eleventh 
vertebra. The postzygapophyses look as much outwards as down- 
wards, or even mainly outwards. 

In the eleventh dorsal vertebra the neural spine projects more or 
less forwards (Fig. 17, n s ), instead of backwards, abutting against 
that of the tenth vertebra, which it may, or may not, slightly 
exceed in length. It has no transverse process, but there are 
two conspicuous processes on each side, which evidently answer 
to the processes (one at each end) which terminate the transverse 
process of the tenth vertebra, but which, in the eleventh vertebra, 
are quite separated the one from the other. 

The anterior process (Fig. 17, n w ), which projects forwards, 



chap, ra.] SKELETON OF TEE HEAD AND TRUNK. 39 

upwards and outwards, outside the prezygapophysis, is termed the 
mammillary process, or Metapophysis. 

The posterior process (a), which projects "backwards as much as 
any other part of the vertebra, is called the accessory process, or 
Anapophysis. 

The prezygapophyses look almost entirely inwards, while the 
postzygapophyses (5) look almost entirely outwards. 

The twelfth and thirteenth dorsal vertebrae are like the eleventh, 
but their anapophyses are stouter and their neural spines are larger 
and project more forward. 

§ 7. The seven lumbar vertebras are larger and more massive 
than the dorsal vertebrae, and increase in size as we proceed back- 
wards as far as the sixth lumbar (see Fig. 23). 

Selecting the fifth for comparison with the fifth dorsal, we find its 
centrum broader in proportion to its depth, about twice as long, 
less convex transversely below, and 
with a slight median ridge, called 
hypapophysial* running from before 
backwards, along its under surface. 
The neural lamina and pedicel are 
much longer, and the latter, though 
deeply notched behind, is scarcely at 
all so in front. 

The neural spine is very much 
shorter, absolutely as well as relatively. te^Ih II^Ileveoth verteb™ 
It is elongated from before backwards, slightly separated. 
and inclines forwards instead of back- 1l jsSSiS^SEtea. 

wards, thus agreeing with the last "• Anapophysis. 

. _ ' _ \> . B d. Tubercular process. 

three dorsal vertebrae. m. Metapophysis. 

mi i j/l • i i »• Part of transverse process 

Ine zygapophyses are thicker, and which conceals from view 

their articular surfaces are differently p c^tSproS?" 

shaped from those of the dorsal vertebrae. s - Keurai spine. 

-J, 1 , . , /» Z. Anterior zygapophvsis. 

Each prezygapophySial Surface IS 3. Posterior zygapophysia. 

concave, and looks inwards as well as 

upwards. The postzygapophysial surfaces are convex, and look 
outwards as well as downwards, being embraced by the pre- 
zygapophyses of the vertebra next behind. The transverse processes 
are very much longer than those of the dorsal vertebrae, and project 
very much forwards and strongly downwards as well as slightly 
outwards. There are no capitular or tubercular surfaces, the 
lumbar vertebrae not bearing ribs. 

The metapophyses and anapophyses are large and conspicuous, 
though not more so than in the last dorsal vertebra. 

The neural canal is larger and more quadrangular than in the 
dorsal region. 

The more anterior lumbar vertebrae closely resemble the more 

* Because it represents a certain process, present in many other animals, 
which is called a hypapophysis. 




40 



THE CAT. 



chap. m. 



posterior dorsal vertebrae, the first lumbar being quite like the ast 
dorsal, except that it has no capitular surface, but, in its place, a 
short forwardly extending transverse process, and that the niet- 
apophyses are somewhat larger. 

As we proceed backwards through the series of lumbar vertebrae, 




Fig. 18. — Fifth Lumbar Vertebra. 



a. Anapophysis. 
c. Centrum. 
to. Metapophysis. 
n. Neural lamina. 



s. Neural spine. 
t. Transverse process. 
z. Prezygapophysis. 
3. Postzygapophysis. 



the anapophysis decreases, so that in the sixth lumbar there is but a 
minute rudiment of such a process. The metapophysis is at its 
maximum in the fourth lumbar vertebra, but is large even in the 
last. The neural spine is longest at the fourth. The transverse 
process increases rapidly from the first lumbar vertebra to the 
fourth, and is slightly longer in the fifth and sixth lumbar vertebrae. 
The zygapophyses continue to be directed as in the fifth lumbar 
vertebra, except that the postzygapophyses of the seventh look 
once again more downwards. 

The centrum of the seventh lumbar vertebra is not longer than is 
that of the first, and the same is the case with the neural arch. 

§ 8. Having noted the characters of the vertebrae next behind the 
dorsal ones, we may advance to those in front of them. 

Of the seven cervical vertebrjb the first two are sufficiently 
exceptional to demand separate notice. The other cervicals are very 
much alike, but the fifth may be selected for comparison with the 
fifth dorsal vertebra. 

Its centrum is relatively wider from side to side and narrower 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 



41 



from above downwards than in either the dorsal or the lumbar 
vertebrae. The front surface of the centrum is convex, and looks 
much downwards as well as forwards, and its hinder surface is 
concave and looks much upwards as well as backwards. The 
pedicle is narrow from before backwards, and its anterior notch is 
as marked as its posterior one ; but this appearance is mainly due 
to the projection forwards of the prezygapophysis (s). The neural 
laminae are much flattened, and are broadened transversely like the 
centra. The spinous process is short, small, and projects somewhat 
forwards. The zygapophyses are large and flat. The articular 
surface of each prezygapophysis looks upwards, forwards, and 






Fig. 19.— Fifth Cervical Vertebra. 



A. Side view. 

B. Front view. 

C. Back view. 
c. Centrum. 

s. Neural spine. 



t. Transverse process. 
v. Vertebral canal. 
z. Prezygapophysis. 
3. Postzygapophysis. 



slightly inwards. Its outer surface presents a roughened pro- 
minence. The articular surface of each postzygapophysis looks 
downwards, backwards and slightly outwards. 

There is a large plate-like transverse process (t) which springs 
from two roots. One of these descends from the front of the side 
of the pedicle, the other projects from the centrum, just at the place 
where the capitular articular surface of a dorsal vertebra is placed, 
and so may be called a " capitular process." These two short roots 
unite and enclose a space (v) called the vertebral canal, because it is 
traversed by the vertebral artery. Thus this vertebra may be said 
to have " perforated transverse processes." Beyond the junction of 
its two roots the transverse process expands into an irregularly 
quadrilateral plate, one surface of which looks outwards, upwards, 
and slightly forwards, while the other looks inwards, downwards, 
and slightly backwards. From near the hinder angle of this plate 
a process, somewhat like an anapophysis, projects upwards and 
backwards, so that the plate may be said, at this part, to slightly 
bifurcate. 

The other cervical vertebrae (except the first two) more or less 



42 



THE CAT. 



[CHAP. III. 



closely resemble the fifth cervical. The seventh, however, has a longer 
spinous process (like that of a dorsal vertebra), and no vertebral 
ganal — only that part of the transverse process being developed, 
which corresponds with root above the vertebral canal and with 
the an apophysis- like process of the transverse process of the fifth 
vertebra. These parts, therefore, may be taken to represent the 




Fig. 20.— The Axis Vertebra. 



A. Side view. 

B. Front view. 

C. Back view. 

D. Dorsal view. 

E. Ventral view. 



al. Anterior articular surface. 

c. Posterior articular surface of centrum. 

o. Odontoid process. 

s. Neural spine. 

t. Transverse process. 

z. Posterior zygapophysis. 



tubercular process of a dorsal vertebra, while the rest of the cervical 
transverse process, where present, represents a rib. " 

The sixth cervical vertebra has the anapophysis-like process very 
large, while the lamellar transverse process is much developed 
behind and within it, so that the process of bifurcation, which was 
incipient in the fifth cervical, is, in the sixth, so advanced that the 
transverse process may certainly be said to bifurcate posteriorly. 

In the fourth and third vertebrae the transverse process becomes 
simpler and relatively more extended from before backwards, but is 
always perforated. 



CHAP. III.] 



SKELETON OF THE HEAD AND TRUNK. 



43 



The convexity outside the prezygapophysis is at its maximum in 
the fourth vertebra. It is really a rudimentary metapophysis. 

The neural laminae of the sixth and seventh vertebrae show a 
ridge-like process on the inner side ot each postzygapophysis. This 
is called a hyperapophysis. 

§ 9. The second cervical vertebra, termed the axis, diners con- 
spicuously from every other bone of the spine in having a large blunt 




Fis 21.— Tre Atlas Vertebra. 



A. Side view. 

B. Front view. 

C. Back view 

D. Dorsal view. 
£. Ventral view 



/. Foramina. 

n. Neural lamina. 

s. Rudiment of neural spine. 

t. Transverse process. 

z. Articular surfaces. 

yi Hypapophysial tubercle. 



process of bone (like a tooth or peg, o), extending forwards from 
the anterior portion of the centrum — on which account the bone is 
sometimes termed the vertebra dentata. This eminence is called the 
odontoid process. It presents a smooth articular surface below, and 
a smo(,th groove above. The lower surface of the rest of the 
centrum of the axis exhibits a median hypapophysial prominence 
or ridge. The pedicle has a very deep anterior notch, beneath 
which is an anterior lateral articular surface (al), instead of a pre- 
zygapophysis. The neural spine (s) is merely an elongated ridge 
extending along the summit of the stout neural laminae. 

The postzygapophyses (s) exist as usual, but the prezygapo- 
physes are, as has just been said, absent. There is however instead, 
on each side, the just mentioned large articular surface (al), looking 
forwards and outwards, and supported on the centrum, beside but 
behind the odontoid process. The transverse process (t) is short, 
pointed, perforated, and backwardly projecting from near the 
hinder end of the side of the centrum. 



44 THE GAT. [chap. in. 

§ 10. The first vertebra of all, called the atlas, also differs con- 
spicuously from every other bone of the spine. It differs by the 
large size of the aperture it encloses and by the smallness of the part 
which, at first sight, appears to represent the centrum, as also by 
the absence of a neural spine. The ring it forms is wider above 
than below, and it is this wider part which corresponds to the 
neural arches of the other vertebrae. The narrower ventral part 
receives upon it the odontoid process of the axis. The part which 
seems to, but does not truly represent the centrum, articulates by 
its upper surface with the under surface of the odontoid process, 
while its own under surface developes a slight median prominence (y) 
or hypapophysial tubercle. The neural arch (n) is slightly wider 
from behind forwards than in the other cervical vertebrae, and there 
is no neural spine, or only a minute rudiment of it (s). Each 
neural lamina is perforated just above the anterior articular surface 
(Fig. 21, B, /). The vertebral artery and sub-occipital nerve 
traverse this foramen. The sides of the atlas vertebra are termed 
" the lateral masses," and give rise to the great, wing-like, trans- 
verse processes (f), and to large anterior and posterior articular sur- 
faces. There are no true zygapophyses. The transverse processes are 
longer and larger than in the other cervical vertebrae, and consist 
of a tubercular and capitular process, united at their distal ends, 
or enclosing a small foramen for the vertebral artery (Fig. 21, 
C and D,/), and then expanding into a plate of bone, one side of 
which looks upwards and the other downwards. Of the four large 
articular surfaces two are situated behind the root of each transverse 
process (Fig. 21, 0, z), and correspond in position with the anterior 
articular surfaces of the axis, before described. The anterior pair 
of surfaces (Fig. 21, B and E, z) are very large, cup-shaped, and oval, 
converging interiorly, and looking inwards as well as forwards. 
They receive and articulate with two prominences of the hinder 
end of the skull. At the inner margin of each is a minute, smooth, 
rounded tubercle. The hinder pair of articular surfaces (Fig. 21, 
C and D, z) are smaller than the anterior pair, and are more elongated 
in shape and flatter. They are inclined a little inwards as well as 
upwards and backwards, and join the anterior articular surfaces of 
the axis vertebra. 

The atlas is formed to turn on the odontoid process of the axis as 
on a pivot, as will be further explained when the ligaments come 
to be described. 

§ 11. Next to be noticed are the three (sometimes four) vertebrae 
which are often called u false," because they anchylose together into 
one bony mass, and so constitute the sacrum. 

This bone immediately succeeds the hindmost lumbar vertebra, 
and is roughly quadrangular in form, but the transverse; diameter of 
its hinder end is considerably less than that of its anterior portion. 

The composite nature of the sacrum is plainly manifested (in the 
fully ossified bone of even the most aged individuals) by its processes 
and perforations, and by the transverse markings of its ventral surface. 



chap, in.] SKELETON OF TEE HEAD AND TRUNK. 



45 



Its first component vertebra is considerably larger than the two suc- 
ceeding ones, which are about equal in size. 

The ventral surface of the sacrum (A) is markedly concave from 
before backwards, and is also concave transversely at its more an- 
terior part. It is marked by two transverse lines (which indicate 
the original limits of the vertebral centra), and at each end of each 
line is a considerable aperture or foramen (/). These four open- 
ings, called the ventral sacral foramina, give exit to the anterior 
divisions of the sacral nerves. 




—The Saprum 



A. Ventral view. 

B. Dorsal view. 

C. Front view. 

c. Anterior central articular surface. 
/. Foramina. 



I. Lateral masses. 

m. Rudiments of zygapophyses and metapo 

physes conjoined. 
s. Neural spines. 
z. and 3. Zygapophyses. 



The dorsal surface of the sacrum is rough, and exhibits three 
neural spines (is) projecting nearly straight upwards. They are all 
shorter than the neural spine of the last lumbar vertebra, and the 
third sacral neural spine is much smaller than the two in front of 
it, whereof the first is the taller. 

External to the neural spines, and at the outer margins of the neural 
laminae (which form a completely roofed neural canal throughout 
the sacrum), there are, on each side, four eminences, representing 
zygapophyses or metapophyses, or both(wz). Thus at the anterior 
end of the centrum we have (z) on each side a prezygapophysis 
(with its outer margin prolonged by the metapophysis), which is 
like that of the last sacral vertebra, except that it is somewhat 
larger. Behind this there is a smaller prominence, which represents 
the conjoined metapophysis and zygapophysis anchylosed together 
at the junction of the first and second sacral vertebrae. Behind this, 
again, there is another still smaller prominence which represents the 
same parts at the junction of the second and third sacral vertebrae. 
Behind this again, and close behind the third sacral neural spine, is 
a third process (which is the postzygapophysis of the third sacral 
vertebra) which articulates with the first vertebra of the tail (5). 

Just external to each process formed of coalesced and anchylosed 
zygapophyses, is a considerable aperture or foramen. There are 
four such, and these are termed the dorsal sacral foramina, and they 



46 THE CAT. [chap. hi. 

are placed directly over the ventral sacral foramina before described. 
The bony substance of each sacral vertebra projects outwards beyond 
these foramina, forming what is called the " lateral masses " of the 
sacrum (/), which are in fact the coalesced transverse processes of 
the sacral vertebrae. 

The formation of the ventral and dorsal sacral foramina may be 
thus explained. Nerves in the true vertebrae pass out, as we have 
seen, between the pedicles of adjacent vertebrae. Now the coa- 
lescence of the sacral transverse processes necessarily changes each 
such intervertebral opening into a pair of openings, of which one is 
dorsal and the other ventral. 

In a line connecting each pair of dorsal sacral foramina, slight 
irregular perforations in the roof of the neural canal indicate the 
primitive interspaces which existed between adjacent sacral vertebrae. 
At the anterior end of the sacrum is an articular surface (c), 
very wide but narrow from above downwards, which joins the 
centrum of the last lumbar vertebra. Above this is the opening of 
the neural canal, also greatly extended transversely, and narrow 
from above downwards, and the prezygapophyses and neural spine 
before mentioned. Extending out from each side of the front 
articular surface of the centrum are the two " lateral masses," which 
project strongly outwards, downwards, and somewhat forwards. 

At the posterior end of the sacrum there is a small oval articular 
surface, which joins the centrum of the first caudal vertebra. On 
each side of it the "lateral masses" — here small, thin bony r plates — 
project outwards. Above it is the small crescentic opening of the 
hinder end of the sacral neural canal, surmounted by the neural 
spine and postzygapophyses (s) before mentioned. 

The sacrum, viewed laterally, exhibits the neural spines, zyg- 
apophyses, and dorsal foramina before described, and below these, 
one of the lateral masses, which appears deep in front and tapers 
rapidly backwards. On its deep part is a large irregular surface, 
which in the living animal is coated with cartilage, and articulates 
with the hip or haunch- bone. This surface is somewhat crescentic, 
with the concavity upwards, and is called the auricular surface, because 
the corresponding part in man has an outline somewhat resembling 
an ear. Above this surface the lateral mass is more or less excavated 
and uneven. The auricular surface may be entirely supported by that 
part of the lateral mass which pertains to the first sacral vertebra ; it 
may, however, extend m to part of that pertaining to the second 
sacral vertebra. That part which pertains to the third sacral vertebra 
ends behind in a pointed process extending outwards as well as 
backwards to about the level of the middle of the sacrum's hinder 
central surface. 

§ 12. The last part of the cat's spine is formed by the caudal 
vertebkje (see Fig. 23), usually about eighteen or nineteen in 
number, but sometimes as many as twenty-four. Of course the 
short-tailed breeds have only a few caudal vertebrae. In the Manx 
cat there are four, and in the Malay cat several of the vertebrae 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 47 

towards the middle or more distal part of the tail are distorted, 
atrophied, and more or less fused together at the place where the 
tail is so suddenly contorted. 

With age, the first caudal may anchylose with the third sacral 
vertebra, which it resembles much both in size and shape, though 
its neural spine is smaller and its transverse process (which projects 
strongly backwards and slightly outwards) is narrower from behind 
forwards than is the lateral mass of the third sacral vertebra. The 
two next caudal vertebrae closely resemble the first, though they are 
slightly longer. The fourth caudal vertebra is again longer, its 
neural spine is hardly to be detected, and its shorter transverse 
processes project outwards and backwards from the hinder part of 
the side of its centrum. Two slight hypapophysial prominences are 
also to be detected side by side and but little separated, at the 
anterior end of the ventral surface of the centrum. The neural 
canal is also much reduced in size. The fifth caudal vertebra 
exaggerates the same characters, as also does the sixth, in which 
the neural canal is very small. Here also a minute transverse 
process begins to show itself projecting outwards from the anterior 
end of each side of the centrum, while that projecting from its 
posterior end is so reduced as to be scarcely, if at all, larger than is 
the transverse process thus newly appearing at the anterior end of 
this vertebra ; in which, moreover, the prezygapophyses no longer 
articulate with the postzygapophyses in front of them. 

In the seventh caudal vertebra the minute neural canal is hardly 
enclosed by bone, and is only so near the median part of the bone. 
The prezygapophyses are the longest processes, and the anterior 
transverse processes are rather longer than the posterior ones. The 
transverse processes in the eighth vertebra are hardly more prominent 
than are the hypapophysial ones, but the whole bone continues to 
increase in length. In the ninth vertebra there is an open groove 
instead of a neural canal. The tenth is about the absolutely longest 
vertebra. Thence onwards the processes become less and less marked, 
and the vertebrae, from the eleventh or twelfth, begin manifestly to 
decrease in length and all other dimensions — the last vertebrae being 
little more than small cylindrical ossicles, each formed of a centrum 
only, with faint indications at each end of processes corresponding 
with those described as existing in the more anterior vertebrae. 
Thus the last vertebra is the very opposite to the first (or atlas), 
being all centrum, while the atlas has no proper centrum at all. 

Certain very small Y-shaped bones called chevron bones are arti- 
culated beneath the interspaces and adjacent ends of the caudal 
vertebrae, from the second to the tenth or eleventh vertebra. 

§ 13. The whole sekies of vertebrae thus form a jointed rod — 
the spinal or vertebral column. Its component vertebrae, moreover, 
are so disposed that the backbone, when seen in profile, presents, 
between the atlas and the tail, two curvatures (see ante, 
Fig. 2), directed alternately upwards and downwards. Thus the 
cervical vertebrae form a curve which is convex downwards, while 



48 



THE CAT. 



[CHAP. III. 



> I 



') 



ca 



Fig. 23. — Ventral 

ASPECT OF THE VER- 
TEBRAL Column. 

c. Cervical, 

d. DoiriI, 
I. Lumbar, 

s. Sacral, and 

ca. Caudal vertebrae. 



the dorsal and lumbar vertebrae together form 
a curve which is much more strongly convex 
upwards than the preceding curve is convex 
downwards. The neural spines (which are longest 
in the dorsal vertebrae) change their direction at 
about the middle of the posterior curve, that of 
the tenth dorsal vertebra inclining backwards, 
and that of the eleventh forwards, their junction 
indicating the centre of motion. 

The breadth of the ventral part of the back- 
bone {i.e. the transverse diameter of the vertebral 
centra), narrows slightly from the axis to the first 
dorsal vertebra ; it remains much the same to 
about the fifth, and then gradually widens to the 
first sacral, whence it again decreases rapidly 
to the beginning of the tail, and then very 
gradually to the end of that organ. The width 
of the column, including the transverse pro- 
cesses and the lateral masses of the sacrum, is 
at its maximum at once at the atlas, and sud- 
denly decreasing at the axis. It thence remains 
much the same, but gradually broadens to the 
first dorsal, whence it again very gradually 
narrows to the last dorsal vertebra. Thence it at 
once increases rapidly to the last lumbar vertebra, 
w r hich is about as wide as is the atlas. Thence 
backwards the spine gradually narrows to the end 
of the vertebral series. 

The ventral surface of the vertebral column 
bears no median prominence save the slight 
longitudinal one beneath the centrum of the axis, 
and of certain lumbar vertebra?, together with the 
tubercles of the atlas and of some caudal vertebrae 
and the chevron bones. The dorsal surface bears a 
median series of spines, which are longest in the 
anterior dorsal and lumbar vertebrae. They are 
variously directed, as has been already described. 

On each side of the series of spinous processes 
are the neural laminae forming the bottom of the 
"vertebral grooves," each of which is bounded ex- 
ternally by the transverse, zygapophysial and 
metapophysial processes, and internally by the 
spinous processes. Each groove is broad and 
shallow in the neck, and deeper and narrower 
in the anterior thoracic region, and deepest of 
all at the lumbar region. The laminae overlap in 
the neck and in the anterior and middle part of 
the dorsal region. They leave an open space 
between them in the lumbar portion of the ver- 
tebral column. 



CHAP. III.] 



SKELETON OF THE BEAD AND TRUNK. 



49 



§ 14. Having considered the dorsal part of the axial skeleton — 
the backbone — we may now proceed to consider that opposite, or 
ventral structure, the breastbone, together with those parts (the ribs, 
with their cartilages), which connect the backbone and breastbone 
together. The breastbone and ribs, with the dorsal vertebras, to 




Fig. 24.— Skeleton op the Thorax. 



c. End of xiphoid cartilage. 
ca. One of the costal cartilages. 
to. Sternebrae of body of sternum 



Xiphoid process. 
Presternum or manubrium. 



which the ribs are dorsally attached, together constitute the skeleton 
of the thorax. The thoracic part of the axial skeleton thus forms a 
sort of bony cage in which, during life, those most important organs, 
the heart and lungs, are sheltered and protected. 

§ 15. The breastbone, or sternum, extends along the ventra 



50 THE CAT. [chap. m. 

portion of the trunk in the middle line, but it is very much smaller 
and less complex than is the backbone. It is flattened from above 
downwards, but still more so from side to side, and consists of a chain 
of eight bones, called sternebra!, about fifteen or sixteen times as long 
as broad, but its width varies slightly at intervals throughout its 
whole extent. 

The sternum is connected on each side with the cartilages (ca) of 
the first nine ribs, one cartilage on each side being attached to each 
successive pair of sternebrse at their junction, as well as to the side 
of the manubrium and the hinder end of the seventh sternebra. 

The first sternebra, which ends anteriorly in a laterally compressed 
pointed process (p), is called the manubrium, or presternum, and 
extends forwards in front of the insertion of the cartilage of the first 
rib. The second part (or the body of the sternum) is made up of all 
the other six sternebreo together. The third part (x) is the xiphoid, 
or ensiform, process, which varies in shape in different individuals, 
and long remains cartilaginous. The hinder end of the manubrium 
affords a surface for the attachment of the second costal cartilage. 

The first sternebra of the body completes the surface for the 
second rib. The notches for the third, fourth, fifth, sixth and 
seventh ribs are situated at the lines of junction of the sternebrse 01 
the body of the sternum — as before mentioned. The notches for the 
eighth and ninth rib cartilages are placed close together at the 
hinder end of the seventh sternebra (see below, Fig. 78, B,/). 

This xiphoid cartilage projects freely backwards, tapering towards 
its generally more or less expanded and fan- shaped distal end (c). 

§ 16. The ribs (costce) are long, slender, curved bones, which 
extend obliquely downwards from the spinal column, and end below 
in cartilaginous prolongations called costal cartilages. Some of these 
join the sternum by their cartilages (Fig. 24, ca), and others do not. 
There are thirteen ribs on each side. The nine anterior ribs on 
each side are called " true ribs," and join the sternum by their 
cartilages. The four hinder ribs do not join the sternum, and are 
therefore called " false ribs." The ribs generally are curved at 
first (starting from their attachments to the vertebral centra) out- 
wards and a little upwards, then backwards, and outwards and 
much downwards. 

Taking the sixth rib as a type, the following points may be 
noted : its proximal or upper and inner end is thickened, and is 
called the capitulum, or head, of the rib (c), and it is this which 
joins the capitular surfaces of the fifth and sixth dorsal vertebraa by 
two corresponding oblique articular surfaces, with a ridge between. 
The part of the rib next to the head is termed the neck (n), and 
this short portion terminates at what is called the tuberculum (t), or 
tubercle of the rib. This is a rounded prominence on the hinder 
border of the bone. It looks upwards, and presents a smooth 
surface for articulation with the transverse process of the sixth 
dorsal vertebra ; outside this smooth prominence is a rough surface 
of bone. The neck of the rib is narrower than is the first part 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 



51 



of the "body," — the "body" of the rib being all that portion 
which is distal to, or beyond, the tubercle. This body (b) is 
somewhat flattened from before backwards at its upper part, and 
slightly expanded in the same direction at its distal end, the in- 
tervening part being nearly cylindrical. It exhibits a faint indication 
of a groove running along its hinder side, especially at the upper 
part of its body. A little beyond the tubercle the bone makes a 
sudden bend downwards (a). This part is termed the angle, and 
it is behind it that the groove just mentioned is most distinctly 
developed, while in front it exhibits a roughened line for muscular 
attachment. 

The distal end of the bone is hollowed out into an oval pit (p), 
and into this the sixth costal cartilage is inserted. 



t ,c 





Fig. 25.- 


—Side View of Ribs. 


A. First rib. 

B. Sixth rib. 

C. Thirteenth rib. 

a. Angle. 

b. Body. 




c. Capitulum. 

n. Neck. 

p. Pit for costal cartilage. 

t. Tuberculum. 



The other true ribs differ but slightly from the sixth, except as 
to length, which decreases as Ave pass forwards or backwards from 
the ninth, which is the longest rib. 

The first rib is the broadest of all (Fig. 25, A), especially towards 
its proximal end. Its capitulum has but one articular surface. The 
" angle " about coincides in position with the tuberculum. 

The false ribs decrease in length backwards, but the last rib is 
longer than even the fourth true rib. 

The three foremost false ribs (the tenth, eleventh and twelfth) 
are united together by their costal cartilages, but the thirteenth 
rib ends freety, and is thence termed a floating rib. The last rib 
(Fig. 25, C), has but a minute rudiment of a tuberculum or none, 
and the capitula of the last three ribs have each but one articular 
surface. 

e 2 



52 THE CAT. [chap. ra. 

The angles of the ribs become more and more distant from the 
tubercula as we pass backwards to the eleventh rib. The thirteenth 
exhibits no angle. 

§ 17. The costal cartilages (Fig. 24, ca), differ much as to 
length, connexion, shape and direction. The tenth is the longest, 
and thence the length decreases as we pass either forwards or 
backwards through the series. The first nine join the sternum. 
That of the tenth rib joins the costal cartilage of the ninth, rib, 
and similarly the eleventh and twelfth costal cartilages unite distally 
with the lower border of the costal cartilage next in front. The 
thirteenth costal cartilage ends freely. The first costal cartilage 
is the broadest, and thence they gradually narrow backwards. The 
last cartilage is pointed at its distal end. The upper (proximal) 
end of each costal cartilage is convex, and fits into the distal con- 
cavity of its rib. As to direction, the cartilages pass at first 
backwards, then downwards, curving distally forwards from the 
fourth to the seventh. The first cartilage has a nearly horizontally 
forward direction, while the last extends downwards and backwards. 

§ 18. The thorax as a whole' forms a long, transversely narrow, 
conical case, with a small aperture in front and a wide oblique 
opening behind. It is considerably deeper from above downwards 
than it is wide from side to side. The variation in its dimension, 
which shows itself as we proceed, from before backwards through 
the thorax, is produced by the corresponding variation in the length 
of the ribs and in their curvature. The anterior opening is bounded 
by the first pair of ribs, the first dorsal vertebra and the manubrium. 
The posterior opening is bounded by the xiphoid process, the cartilages 
of the four hindmost ribs, the body of the thirteenth rib and the 
thirteenth dorsal vertebra. 

§ 19. Such being the structure of the bony and cartilaginous parts 
which make up the spinal portion of the axial skeleton, we have 
next to consider the fibrous bands, or ligaments, which hold together 
the bones and cartilages already described. The substance inter- 
posed between each pair of true vertebrae is an elastic body termed 
an intervertebral disc. 

Each such disc is made up of concentric lamellae (Fig. 26, /), of 
fibro-cartilaginous and fibrous tissue, surrounding a soft central por- 
tion (g), which is very elastic (projecting beyond the general level of 
the disc when pressure is removed) and contains numerous nu- 
cleated corpuscles like those of cartilage. 

The surface of each centrum is covered (except towards its cir- 
cumference) with a thin layer of cartilage, and it is to it that the 
intervertebral discs are attached. 

These discs form so many elastic pads, and one such is placed 
between each pair of presacral vertebrae, except between the atlas 
and the axis. 

A strong band of fibres, called the ventral common ligament, extends 
along the ventral surface of the vertebral bodies. It is thickest 
where it passes over the middle of the centra than elsewhere, and 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 



53 



thus tends, by filling up depressions, to render the surface of the 
vertebral column more even. 

Another band of fibres, called the dorsal common ligament, passes 
backwards within the neural canal along its ventral surface from the 
skull backwards. 

Each pair of articulating zygapophyses is surrounded and enclosed 
by a fibrous bag, the fibres passing from one zygapophysis to the 
other. Such a surrounding and enclosing membrane is termed a 
capsular ligament. Enclosed within the capsular ligament is a 




Fig. 26. — Intervertebral Discs. 



A. Surface view enlarged. 

B. Section through two discs. 
/. Lamellae. 



g. Soft central portion. 
i. Interspinous ligaments. 



membrane which secretes an albuminous fluid termed synovia. 
Membranes of the kind are therefore termed synovial, and are 
placed between hard parts which are destined to move one on the 
other. Synovial membranes will be more fully noticed in the descrip- 
tion of the different kinds of joints at the end of the next chapter. 

Certain ligaments with much yellow elastic tissue, called the liga- 
menta subflava, pass between the neural lamina, being attached to the 
inner or ventral surface on one neural lamina and thence passing 
backwards to the anterior margin of the neural lamina next behind. 
They are thus best seen when the neural arches are removed and 
viewed on their ventral aspect. 



54 TEE CAT. [chap. hi. 

Adjacent spinous processes are also connected together by mem- 
branes (Fig. 26, B, i), called interspinous ligaments. Narrow bundles 
of fibres, forming a sort of cord, pass backwards along the spinous 
processes. These are the supraspinous ligaments. 

A forward prolongation of these supraspinous ligaments is termed 
the ligamentum nucha, and passes from the cervical neural spines to 
the skull. 

Adjacent transverse processes are also connected together by 
fibrous bands termed the inter-transverse ligaments. These are 
largest in the lumbar region, while they are rudimentary in the 
vertebra? of the neck. 

The mobility of the spinal column is different in different regions, 
being greatest of course in the tail (save in some breeds), which can 
be bent freely in any direction owing to the absence of interlocking 
bony processes, except in the most anterior caudal vertebra?. After 
the sacrum, the mobility is least in the dorsal region, on account of 
the overlapping of the neural laminae. In the cervical region there 
is much mobility, even apart from the axis and atlas, the motions of 
which will be treated of separately. Lateral bending and rotation 
are variously limited by the direction of the articular surfaces of the 
zygapophyses, which, as has been noted, are different in different 
regions. 

§ 20. The axis and atlas articulate together in a manner 
altogether peculiar. The atlas (with the head to which it is attached) 
can turn round to a great extent in either direction upon the odon- 
toid process as on a pivot, being retained in place by ligaments. 
Synovial membranes are interposed between the articular surfaces of 
the atlas and axis, which surfaces are kept in apposition by capsular 
ligaments. 

The odontoid process is kept in place by the transverse ligament 
of the atlas, which extends across above that process and between 
the internal margins of the anterior articular surfaces of the atlas. 
From the midst of this transverse ligament two bundles of fibres 
are given off in opposite directions, one bundle passing backwards 
to the centrum of the axis, the other forwards to the skull, thus 
giving rise to the figure of a cross. 

A synovial membrane is placed both above and below the odontoid 
process, corresponding with the two smooth surfaces which have 
already been noted as existing upon it. 

Three ligaments pass forwards from the odontoid process to the 
skull, i.e., one from its tip to the margin of the opening of the skull 
in front, and two others (called alar or check ligaments) from the 
sides of the summit of the process to the inside of the condyles of 
the skull. 

These crucial and odontoid ligaments are covered over above and 
sheltered by another called the occipito-axial ligament, which is 
placed in the ventral part of the neural canal between them and the 
most anterior part of the dorsal common ligament. It passes up 
from the centrum of the axis to the inside of the floor of the skull. 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 55 

Another ligament, the ventral occipito-atlantal ligament, passes 
from the front ventral border of the atlas forwards to the adjacent 
part of the skull, and similarly the ventral atlanto-axial ligament 
connects the ventral arch of the atlas with the centrum of the 
axis. Certain other ligaments connect together the neural arch of 
the atlas with that of the axis and with the skull. The first of 
these is the dorsal atlanto-axial ligament, connecting the neural 
arches of the axis and atlas. Another is the dorsal occipito-atlantal 
ligament (Fig. 27, 1 ), which connects the neural arch of the atlas 
with the adjacent margin of the posterior aperture of the cranium. 
A third ligament, the transverse atlanto-occipital ( 5 ), passes outwards 
upwards and forwards on each side from the neural arch of the atlas 
to the inner side of the adjacent occipital condyle. Yet another liga- 
ment may be called interspinous. It connects the neural spine of the 
axis with the middle of the dorsum of the neural arch of the atlas. 

§ 21. As to the ribs, a ligament, named " stellate" passes, in a 




Fig. 27.— Ligaments of Atlas and Axis. 



1. Dorsal occipito-atlantal ligament. 

2. Dorsal atlanto-axial ligament. 

3. Interspinous ligament. 



4. Rectus lateralis muscle. 

5. Transverse atlanto-occipital ligament. 
so. Supra-occipital. 



radiating manner, from the ventral surface of the head of each rib 
on to the intervertebral substance opposite to it, and on to the bodies 
of the two adjacent vertebrae. 

Another ligament, named inter-articular, passes transversely from 
that ridge on the head of the rib which divides its two articular 
surfaces, to the intervertebral substance. This ligament of course 
does not exist in the articulations of the first, eleventh, twelfth, and 
thirteenth ribs, which have each but one articular surface. 

The ribs, except the first and the last three, are also connected 
with the transverse processes, each by certain other ligaments ; but 
none of these attachments prevent each rib from performing a slight 
movement backwards and forwards upon its vertebral attachment, as 
well as a certain movement of rotation. 

The pieces of the sternum are connected by cartilage, and bound 



56 



THE CAT. 



[CHAP. III. 



together both in front and behind by ligamentous fibres, and such 
fibres surround the articulations of the costal cartilages with the 
sternum, and thence radiate over the latter both dorsally and 
ventrally. The various articulations of the ribs with the vertebrae 
and of the costal cartilages with the sternum, are furnished with 
synovial membranes. Thus a movement of the ribs backwards and 
forwards alternately is facilitated, and such movements, we shall 
hereafter see, are continually repeated in the process of breathing. 



THE SKELETON OF THE HEAD. 

§ 22. The remaining part of the axial skeleton is that familiarly 

pm 




Fig. 28.— The Skull, viewed Dorsally. 



/. Frontal. 

j. Malar. 

I. Lachrymal 

I*. Lachrymal foramen. 

la. Lambcloidal ridge. 

m. Maxillary. 

n. Nasal. 

p. Palatine. 

pf. Post-orbital process of frontal. 



pj. Post-orbital process of malar. 

pm. Prernaxilla.- 

s. Sagittal suture. 

x. Posterior pier of zygomatic arch. 

1. Incisive foramen. 

2. Infra-orbital foramen. 

4. Posterior palatine foramen. 

5. Spheno-palatine foramen. 



known as the skull. This bony structure affords shelter to the 
brain, and is also the seat of certain organs of special sensation — 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 57 

namely, those of hearing, sight, and smell. It may be described 
as an irregularly and complexly shaped osseous box with an arch, 
like a flying buttress, on each side, all forming one coherent mass, 
and with very diversely conditioned arches appended below and not 
similarly coherent. The first of these inferior arches is the skeleton 
of the lower jaw, or mandible. The second is the bony framework 
to which the tongue is attached, the hyoid. Both these inferior 
arches readily fall away from the rest of the skull when the soft 
parts are dissolved or otherwise removed. 

Apart from these arches (both inferior and lateral) the skull 
consists of a spheroidal posterior portion (p), to which is annexed 
in front an elongated, narrower, and irregularly quadrilateral part, 
made up of the bones of the face. On each side of the skull (just 
in front of the spheroidal portion) is a large smooth concave surface 
(with the concavity outwards), which forms the inner wall of the 
chamber for the eye, or the orbit ; and the skull is especially narrow 
from side to side at the hinder and lower part of this region. 

The greater part of the upper region of the skull is smooth and 
even, and crossed by undulating lines of bony union called sutures(s). 

When a section is made lengthways (Fig. 49) through the skull, 
its spheroidal portion is shown to bound a great posterior cavity (for 
the brain), in front of which is a more solid region — the quadrangu- 
lar part — which includes the bones of the nose (Figs. 49 and 50, 
me, et), and is placed above the mouth and between the eyes. 

The skull consists of two parts : — 

(1). The brain-case, skuli proper, or cranium, 
(2). The skeleton of the face. 

Certain conspicuous openings and prominences are found in different 
regions. 

The projecting portion of the back of the head is termed the 
occiput, and at its inferior hinder part is a large hole, looking down- 
wards and backwards, termed the occipital foramen, or foramen 
magnum (Figs. 29 and 4.7, fm). On each side of this hole, forming 
part of its margin, is a rounded projection ; and these projections 
(Figs. 29 and 47, oc), termed " occipital condyles," articulate with 
the cup-shaped articular concavities on the anterior side of the atlas 
vertebra (Fig. 21, B, %), Thus, all but the front part of this foramen 
(to which the odontoid process is attached by ligament) coincides with 
the corresponding portion of the ring of the atlas vertebra, and the 
interior of the skull forms the expanded anterior end of the vertebral 
neural canal. 

If the skull be turned base upwards (Fig. 29) a large globular 
prominence (b) will be seen a little in front of and external to each 
occipital condyle. Each such prominence is called, from its connec- 
tion with the internal ear, an auditory bulla. Between the bullae, 
the under surface of the cranium extends forward as a narrow flat 
surface (Fig. 29, bo and^-s-), bounded laterally by two low, elongated 
bony plates (pt), external to which is, on either side, the wide cavity 
of the orbit enclosed by the bony arch just referred to, which arch is 



58 



THE CAZ 



[CHAP. III. 



termed the zygoma (Z). At the hinder end of the zygoma is a trans- 
versely extended, smooth concavity called the glenoid, surface (g). 
The under surface of the face (formed by the bones of the roof of 




Fig. 29. — Under Surface of Skull 
The two openings enclosed by the pre-maxillse and maxillae, are the anterior palatine foramina. 



6. Auditory bulla. 
bo. Basi-occipital. 
bs. Basi-sphenoid. 
c. Canine. 

fm. Foramen magnum. 
g. Glenoid surface. 
i. Incisors. 
j. Malar, 
m. Maxilla. 
mo. Molar. 
tos. Mastoid process. 
oc. Occipital condyle. 

pp. Palatine (placed one above, the other be- 
neath the opening of the posterior naras). 



pf. Post-orbital process of frontal. 

pj. Post- orbital process of malar 

pm. Pre-maxilla. 

pmo. Pre-molars. 

pp. Par-occipital process. 

ps. Pre-sphenoid. 

pt. Pterygoid process. 

so. Supra-occipital. 

Z. Posterior root of zygoma. 

3. Palatine foramen. 

8. Sphenoidal fissure and foramen rotundus. 

9. Foramen ovale. 

10. Eustachian opening. 

11. Foramen lacerum posterius. 



the mouth) lies at a slightly different level from that of the base of 
the cranium. The two low, elongated bony plates (pt) just spoken 
of connect these two surfaces together on each side, but in the 
middle line, leave a vacuity between them, which is the hinder 
opening of the nostrils, or posterior nares (shown, in Fig. 29, by the 



chap, in.] SKELETON OF TEE HEAD AND TBUNK. 



59 



shadow in front of ps), which bounds the base of the cranium in from 
as the foramen magnum bounds it behind. 

The middle of the hinder part of the under surface of the face 
thus forms the ventral margin of the hinder nostril, while on either 
side, the face receives the termination of the arch of the zygoma. 
It thence narrows as it proceeds forwards, forming a triangular 
bony plate, slightly truncated in front, and bordered by teeth. 

When the skull is looked at in front, we see on each side of its 
highest part, with its rounded outline (the forehead), the great 




Pig. 30. — Skull viewed from in fbont, with the Lower Jaw detached. 



an. Angle of mandible. 

c. Canines. 

c. (Of lower jaw) coronoid process, 

/. Frontal. 

i. Incisors. 

m. Maxilla. 

n. NasaL 



pf. Post-orbital process of fronua*. 

pj. Post-orbital process of malar. 

pm. Pre-maxilla. 

pmo. Pre-molars and inferior true molar. 

y. Condyle of mandible. 

2. Infra-orbital foramen. 

13. Mental foramen. 



sockets for the eyes, termed the orbits. These are not completely 
surrounded by bone, but are bounded below and externally by the 
zygoma and a process (pj), and above by another process (pf) from the 
skull roof, and behind by the wall of the cranium. The part of the 
skull which juts out laterally to support the floor of the orbit is called 
the " malar prominence." Between the orbits is the bony pro- 
minence of the nose, beneath which is a small, somewhat heart- 
shaped aperture, the front bony nostrils or anterior nares. 

Beneath each orbit is the small bony cheek, and the skull is 
bounded below (the lower jaw or mandible being removed) by the 
alveolar border giving attachment to the teeth. 



60 THE CAT. [chap. m. 

When the skull is viewed in profile its upper margin is seen 
to present an even, rounded contour. Its lower margin is 
nearly straight, with irregular prominences. The line of the 
occiput (Fig. 46, c to y) inclines somewhat backwards as it 
ascends. In front, the skull is bounded by the margin of the 
anterior nares. 

The zygoma arches upwards, backwards, and then downwards to 
the front of the auditory bulla, enclosing, as well as the orbit, a 
fossa named "temporal," because a muscle called the "temporal 
muscle" is there placed. Behind and beneath the binder end of the 
zygoma is a noticeable aperture, which is the external bony opening 
of the ear (ae). A ridge also runs upwards from the malar pro- 
minence, and forms the anterior margin of the bony orbit. The 
orbit is bounded behind by an ascending and a descending post- 
orbital process, which nearly meet. 

The skull is said to be divided into certain regions. Thus we 
have the base or basilar region, and opposite to it the vertex, or 
sincipital region ; we have the region of the forehead, or frontal, 
region, and opposite to it that of the back of the head, or occipital 
region. 

At the side of the head we have, posteriorly and above, the 
parietal* region (p) ; beneath this, and within the arch of the 
zygoma, the temporal region. 

The skull is made up of different bones of very different sizes, 
shapes, and degrees of density, which are variously united together 
by sutures. 

When the skull is looked at from above, a transverse zigzag line 
of union is seen to run across behind the forehead; this is called the 
coronal suture. Its zigzag appearance is due to the interlocking of 
little processes which project from the adjacent margins of the bones, 
the presence of which causes the suture (or line of union) to be 
what is called "dentated." Running directly backwards and forwards 
from this, along the middle line of the skull, is another suture — at 
right angles to the former — termed sagittal (Fig. 28, s). The sagittal 
suture ends posteriorly by joining a wide Y-shaped suture with the 
apex upwards, which is called lambdoidal. 

Turning now to the lower jaw ; this when attached to the skull 
is seen to fit, by a cylindrical-shaped head, or "condyle" into a 
depression placed on each side in front of the external auditory 
opening, the glenoid surface before mentioned. 

The number of bones forming the skull decreases with age, by 
anchylosis. In its mature condition the skull of the cat consists of 
the following twenty- seven bones : the occipital, two parietals, two 
frontals, two temporals, the sphenoid, the presphenoid, the ethmoid 
— which ten bones compose the cranium, or skull proper ; two 
maxillaries, two premaxillaries, two nasals, two malars, two lachry- 
mals, two palatines, two turbinals, one vomer, one mandible (in two. 

* Because it is here the "parietal bone" is situate. 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 



61 



parts), and the hyoid bone* — seventeen bones in all, form the 
skeleton of the face. 

§ 23. The occipital bone is of course that of the occiput, and it 
surrounds the great occipital foramen, or foramen magnum (fm). 
When detached, it is seen to be somewhat lozenge-shaped, but 
rounded above and truncated below. It is made up of a crescentic 
plate of bone extending above and beside the foramen magnum, and 
of another narrower and quadrangular plate of bone, which, joining 




A. External surface. 

B. Internal surface. 
bo. Basi-occipital. 
c. Condyle. 

cb. Cerebellar fossa. 




Fig. 31.— The Occipital. 



to. Ex-occipital. 
fm. Foramen magnum. 
I. Lambdoidal ridge. 
p. Par-occipital process. 
so. Supra-occipital. 



the other, bounds the foramen magnum below, and thence extends 
forwards. 

The part above the great foramen (so) is the supra-occipital bone, 
while the parts placed one on each side of it (eo) are the ex-occipitals, 
the quadrangular plate in front (bo) is the basi-occipital, and these 
four are all separate and distinct bones in the young kitten. 

The margin of the supra- occipital projects outwards as a bony 
ridge (/), which descends on each side of the occiput, and is called 
the lambdoidal ridge or occipital ridge, and affords a special surface 
for muscular attachment. The outer surface of the supra-occipitai 
is undulating and more or less convex. Its inner surface presents 
shallow depressions or fossae, one of which (cb) is placed medianly 
above the foramen magnum, and lodges the middle portion of that 
part of the brain called the cerebellum. 

The basi-occipital narrows somewhat as it advances forwards. Its 
upper surface exhibits a smooth concavity, the basilar groove, which 
supports that part of the nervous centres termed the "medulla 
oblongata." 

Each part of the bone which bounds the foramen magnum on 
each side, i.e., each ex-occipital, supports one of the condyles before 



* Really made up of several distinct bones ; but here, for tlie sake of simplicity 
and clearness, spoken of as one. 



THE CAT. 



[CHAP. III. 




noticed. The condyles (c) are elongated convex prominences placed 
somewhat obliquely, converging forwards. The inner border of 
each is rough, for the attachment of one of the " check " ligaments. 
In front of each condyle is a perforation, the anterior condyloid 
foramen (1), which allows the hypoglossal nerve 
to pass out from the brain, while a canal (the 
hinder opening of which is a little within the 
margin of the foramen magnum) traverses the ex- 
occipital on its inner aspect. External to each 
condyle is an expanded process of bone called the 
par-occipital process (p), the front surface of which 
is applied to the posterior surface of the auditory 
bulla. The root of the par-occipital process forms 
the hinder boundary of the aperture of the skull 
through which the jugular vein comes out, which 
aperture is called the foramen lacerum jagalare, or 
foramen lacerum posterius. 

A small triangular bone, the interparietal, in 
the fully mature cat blends completely with the 
supra-occipital, but long remains a distinct ossicle. 
Its base is applied to the mid -part of the superior 
border of the occipital, while its sharp apex extends 
forwards between the parietals. It is strongly con- 
cave within (especially in the transverse direction), 
but is convex externally. 

If this be counted as a part of the occipital, 
that bone may be said to articulate above by its superior margin 
with the parietals, and below this, on each side, with the hinder 
margin of one of the temporal bones, while each par- occipital 
process (as before said) applies itself to the hinder end of one of the 
ordinary bullae. The basi-occipital adjoins the hinder part of the 
bone next in front, namely the sphenoid. 

§ 24. The parietal bone forms, with its fellow of the opposite 
side, the main part of the roof of the cranium. It would be 
quadrangular in figure but that its upper, hinder angle is rounded 
off, and it is strongly convex outwards, and concave within. Its 
greatest convexity is termed the parietal eminence (e). Above this is a 
curved ridge convex upwards, marking the superior limit of the 
temporal fossa. Within, the parietal is marked by grooves for 
blood-vessels, and its upper margin is traversed by a longitudinal 
depression, which forms, with the help of the opposite parietal, a 
longitudinal wide and shallow groove for a blood receptacle called 
the longitudinal sinus. The two parietals are connected together 
above by the sagittal suture ; each is connected by the lambdoidal 
suture with the interparietal, and with the supra- occipital. The 
parietal also articulates anteriorly (/) with the frontal by the 



Fig. 32.— Inter- 
parietal Bone. 

A. Outer surface. 

B. Inner surface. 
a. Apex -which 

passes forwards 
between the pa- 
rietal bones. 

6. Hinder margin. 

c. Fossa for recep- 
tion of part of 
brain. 



* It has not therefore been reckoned as a distinct bone in the list before given 
of the bones of the cranium and face. 



chap tl] SKELETON OF THE HEAD AND TRUNK. 



63 



coronal suture, and below with the temporal bone by a suture (sq) 
which is called squamous, because the margins of the bone it joins 
are so bevilled off that the temporal lies on the parietal like a scale. 
From the hinder margin of the parietal a plate of bone extends for- 
wards at an acute angle, with a'strongly concave free margin. This 
plate divides one part of the brain from another, and is an ossifica- 





A B 

Fig. 33.— Right Parietal Bone. 



A. Internal surface. 

B. External surface. 
e. Parietal eminence. 



/. Surface for articulation with frontal. 
sq. Surface for temporal bone. 
t. Tentorium 



tion of a membrane called the tentorium, and described with the 
brain structures (t). The parietal is always a single bone. 

§ 25. The remaining bones of the roof of the skull are the 
frontals, which lie side by side in front of the parietals, and roof 
over the hinder part of the face as well as the front part of the 
cranium. The suture which divides them is termed the " frontal 




Fig. 34.— The Frontal. 



A. External aspect. 

B. Internal aspect. 

/. Surface joining the other frontal. 
fu. Outer wall of nasal fossa. 
m. Nasal process. 



op Orbital part of lateral plate. 
tp. Temporal part of lateral plate. 
v. Pre-orbital process. 
po. Post-orbital process. 



suture," and is the direct continuation forwards of the sagittal suture. 
The frontals together form a considerable, rather convex triangular 
expansion above, the outermost part of which is the post-orbital 
process (po) of the hinder part of the orbit ; while behind this the 
frontal forms part of the temporal fossa. 

But the greater part of each frontal is its lateral part (op), which 
descends from the outer margin, almost at right angles with its 



64 THE CAT. [chap. hi. 

upper surface, as an undulating plate (concave externally in front, 
and convex behind) with a crescentic inferior margin. The hinder, 
externally convex, part of this plate forms part of the temporal 
fossa; the anterior, externally concave, part of it forms the inner 
wall of the orbit, and (towards its front end) the outer wall of the 
nasal cavity. 

Viewed internally, each frontal shows above, a flattened surface (/) 
for junction with its fellow of the opposite side ; behind this is a 
deep concavity for part of the brain, and in front, a flattened and 
irregularly roughened surface (fa) — the outer wall of the hinder 
part of the nasal cavity. 

Thus, the two frontals together have, when viewed from below, 
somewhat the figure of a bisected hour-glass. There is, behind, a 
large conical cavity (with the apex forwards) for the brain, while 
in front is a smaller conical cavity (with the apex backwards) — the 
nasal chamber. Consequently, when the two frontals are seen together 
from behind, they exhibit a deep median notch, open below, indi- 
cating the point of communication between the anterior and posterior 
conical cavities just mentioned, and situated at the point where each 
frontal is laterally constricted. This notch, in the perfect skull, is 
filled up by a bone called the ethmoid, which forms the hinder end 
of the nasal chamber. At its anterior end, each frontal bifurcates 
laterally into a sharp pointed "nasal process" (m) and a more obtuse 
" pre -orbital process " (p). Between these processes each frontal 
receives an ascending process of the maxillary bone. While the 
two nasal bones are received between the slightly diverging nasal 
processes of the two frontal bones (see Fig. 28). 

Within the substance of the middle upper part of the bone is a 
cavity, more or less filled with air, called the frontal sinus, which 
cavity is prolonged out into the post-orbital process. 

The frontals articulate behind, with the parietals ; laterally, with 
the orbito- and ali- sphenoids, and sometimes also with the temporals; 
below with the palatines, the maxillaries, the ethmoid, and the lachry- 
mals ; in front, with the maxillaries and nasals. 

§ 26. On each side of the hinder part and base of the cranium 
we find an exceedingly complex bone, called the temporal. When 
looked at externally it exhibits a very conspicuous oval opening (the 
meatus auditorius extermis), which is the aperture (me) leading from 
without to the internal ear. From in front of this a bar of bone, 
the zygomatic process (z), arches horizontally forwards and outwards, 
and contributes, with the large plate of bone above it (sq), the 
squamous element of the temporal bone, or the "squamosal." This 
bony plate is convex without and concave within, and with a very 
rounded superior margin, which overlaps the lower part of the out- 
side of the parietal bone above. 

The zygomatic process is somewhat arched vertically, and is bevelled 
off at its distal end, which lies upon the malar bone. At its hinder 
end this process h&s beneath an elongated surface, concave from 
before backwards, and termed the glenoid surface (g). 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 



65 



In its natural state it is coated with cartilage, and serves for the 
articulation of the lower jaw. This surface is limited behind by a 
sharply descending bony plate — the post- glenoid process (gp). A 
ridge of bone is continued backwards from the hinder end of the 
zygomatic process, over the external auditory meatus, and is called 
the posterior root of the zygoma, the part supporting the glenoid 
surface, forming the anterior root of the zygoma. 

The bone which bounds inferiorly the external auditory opening 
is that which forms the auditory bulla already spoken of. This is 
rounded, and smooth on the surface, and rather longer from before 
backwards than transversely. It is at first made of two parts : an 
external part, consisting of a crescentic plate of bone, broader 
in front than behind — the tympanic (so called on account of its 





Fig. 35.— Temporal Bone. 



A. External view. 

B. Internal view. 

6. Inner and larger part of bulla. 

cb. Cerebellar fossa. 

eu. Eustachian opening. 

g. Glenoid surface. 

gp. Post-glenoid process. 

m. Mastoid region. 

me. Meatus auditorius externus. 

mi. Meatus auditorius internus. 



ms. Mastoid process. 

p. Surface applied to parietaL 

sq. Squamosal. 

t. Outer and smaller part of bulla. 

x. Aqueductus cochleae. 

z. Zygomatic process. 

12. Stylo-mastoid foramen. 

A process of the malleus is seen in Fig. A, ex- 
tending downwards and forwards within the 
auditory meatus. 



connexion with the drum of the ear; — and an internal, much wider 
part — the ento-tympanic — which forms all the rest of the bulla, 
which is naturally visible on the base of the skull. 

Between the anterior end of the tympanic and the post-glenoid 
process is a narrow chink, termed the Jissura Glaseri, which transmits 
the chorda tympani nerve. 

At the hinder end of the tympanic, beneath the posterior end of 
the posterior root of the zygoma, is an opening (12), called the stylo- 
mastoid foramen, which gives exit to the facial nerve. Immediately 
below and within this foramen there is a small pit in the tympanic, 
at the bottom of which a minute cylindrical ossicle, called the 
tympano-hyal, may be detected, which serves to give attachment to 
the uppermost and cartilaginous portion of the anterior, or lesser 
cornu of the hyoid (Fig. 46, t*). 

The only remaining part of the temporal bone visible externally 
is a very small and narrow triangular tract, which extends upwards 



66 THE CAT. [chap. hi. 

and backwards (its apex being above) from above the stylo-mastoid 
foramen and behind the posterior root of the zygoma. It is rough 
externally, and forms the lower part of the lambdoidal ridge, the 
upper part of which is formed by the occipital bone. Opposite the 
posterior root of the zygoma it adjoins the par-occipital process, and 
below that point of junction it narrows into a nipple-shaped process 
applied externally to the tympanic, and descending, immediately 
behind the stylo-mastoid foramen, to the pit for the tympano-hyal. 
This triangular tract is the mastoidal region (rn) of the temporal 
bone, and the process just described is the mastoid process (ms). 

On its inner aspect, below and behind the squamous part (sq), 
the temporal bone exhibits a triangular irregularly-shaped mass of 
very dense osseous tissue. This is the petrous part of the temporal 
bone, or the "petrosal.'" The petrous and mastoidal portions of the 
bone enclose the inner and essential parts of the ear, the interna 
canal leading to which — the meatus auditorius intemus — is the con- 
spicuous opening seen on the inner surface of the petrosal {mi). 
This opening is divided within by a horizontal bony lamella into 
two parts. The openings for the auditory nerve filaments are below 
this horizontal lamella, while the opening above it gives entrance to 
the facial nerve, which thence proceeds to the stylo-mastoid foramen, 
traversing in its way a canal termed" the Aqueduct of Fallopius. 

Above the opening of the internal auditory meatus there is, on 
the inner wall of the petrosal, a depression or pit (cb), (which 
lodges a process of the cerebellar part of the brain) surmounted by 
a prominence which indicates the place of the anterior vertical 
semi-circular canal of the internal ear. Below and in front of this 
prominence is a small foramen, the hiatus Fallopii, which transmits 
the superficial petrosal nerve, and leads back into the Aqueduct of 
Fallopius already mentioned. 

Just behind the shallow depression above mentioned, and close to 
the posterior margin of the petrosal, is a small vertically elongated 
opening, called the aquceductus vestibuli. A still smaller aperture 
placed close to and directly behind the internal auditory opening (x) 
is the aqueductus cochleae. Both these openings transmit small 
veins of the internal ear. 

Between the anterior part of the petrosal bulla and. the ali- 
sphenoid is a largish opening (eii), which is that of the Eustachian 
tube — a channel serving to convey air from the mouth to the ear. 
The inner part of the canal is incompletely partitioned off by a small 
bony lamella — (the processus cochleariformis) . This rather con- 
siderable Eustachian aperture is naturally roofed oyer and covered 
by a backward expansion of the ali sphenoid. On the inner side 
of it, at the hinder portion of the junction of the squamosal and 
petrosal portions of the temporal bone, on its inner surface, is 
a groove which receives a venous canal, namely one of the two 
branches into which the median venous channel (before noticed 
as passing along beneath the median junction of the parietals) 
divides as it descends. This groove may lead into a canal opening 



chap, in.] SKELETON OF THE BEAD AND TRUNK. 



6: 



by a foramen just behind the post-glenoid process — a post-glcnoicl 
foramen. This, however, is generally absent. 

The margin of the petrosal, above the cerebellar fossa and 
internal meatus, developes a bony ridge, which unites with the 
tentorial plate, before described as passing downwards and forwards 
from within the parietal. 

The cavity of the bulla is almost completely divided within into 
two very unequal parts by a bony septum which ascends from the 




Fig. 



-Vertical Section of the Auditory Bulla of the Tiger (Flower). 



am. Meatus auditorius externus. 

BO. Basi-occipital. 

e. Eustachian canal. 

ic. Inner chamber of bulla. 

oc. Outer chamber of bulla. 

pt. Promontory of petrosal. 



s. The septum. 
Sq. Squamosal. 
t. Tympanic ring. 

* The aperture of communication between the 
two chambers. 



floor of the bulla. The outer and anterior chamber is much the 
smaller. It is the true tympanic chamber, and has on its outer 
wall a horseshoe-shaped prominence and groove — the tympanic ring 
— to which the tympanic membrane (or membrane of the drum of 
the ear) is attached. It also contains three very small and irregularly- 
shaped bones : (1) the malleus ; (2) the incus ; and (3), the stapes, 
which stretch across from the inside of the tympanic membrane to 
the opposite wall of the petrosal, and are known as the auditory 
ossicles — ossicula auditus — and will be described together with the 
organ of hearing. A long process (munubrium) of the malleus is 
conspicuous (see Fig. 35, A), passing downwards and forwards from 
the upper part of the tympanic cavity. Also the Eustachian tube (e) 
opens into this same outer chamber, superiorly and anteriorly, while 
towards its hinder margin are two holes placed one above another, 

f 2 



68 



THE CAT. 



[CEAP. III. 



situated in the wall of the petrosal, opposite the tympanic memhrane. 
The upper, more anterior, and smaller of these is called the fenestra 
ovatis, the lower and more posterior is the fenestra rotunda. It is 
through these that the really internal ear (a complex memhrane 
which is lodged in a correspondingly complex bony envelope within 
the petrosal) is placed in communication with the exterior (Fig. 1 37). 

The internal, posterior, and much larger chamber, is entirely closed, 
save that a small opening (Fig. 36,*) is left between the hinder part of 
the top of the septum close to the fenestra rotunda, so that this fenestra 
may be said to open into the inner as well as the outer chamber. 

In front of the fenestra rotunda is a bony prominence, caused by 
the presence within it of a part of the internal ear called the cochlea. 





Fig. 37.— The Sphenoid. 



A. Under surface. 

B. Upper surface. 

ox. Anterior clinoid process. 
as. Ali-sphenoid. 
bs. Basi-sphenoid. 
cp. Clinoid plate. 
hp. Hamular process. 
os. Orbito-sphenoid. 
p. Ethmoidal process. 
pf. Pterygoid fossa. 



ps. Pre-sphenoid. 
pt. Pterygoid plate, 
r. Rostrum. 

7. Optic foramen. 

8. Foramen rotundum. 

9. Foramen ovale. 

The anterior and posterior portions are repre- 
sented as separated, and thus the sphenoidal 
fissure (which is defined by their junction) 
is not indicated. 



This prominence is called the " promontory " (pt). Above it, and in 
front of the fenestra ovalis, is a pit, or fossa, within which arises a 
small muscle called the Stapedius. 

The temporal bone, as has been said, is really made up of several 
bones anchylosed together, which were at first distinct. 

Thus we have (1) the squamosal (sq), with its zygomatic 
process (s) ; (2) the tympanic, which forms the outer chamber of 
the bulla (t) ; and (3) the entotympanic, which forms the inner 
chamber of the bulla (b) ; and (4) the minute tympano-hyal. 
Besides these four elements three other distinct ossifications extend 
and coalesce to form the petrous and mastoid portions of the temporal 
bone, and are distinguished by their diverse relations with parts of 



chap, iil] SKELETON OF THE HEAD AND TRUNK 69 

the internal organ of hearing. Continuing our enumeration, we have 
(5) an ossification which gives rise to the upper part of the petrous 
portion (that which is visible inside the skull), and to part of the 
mastoid. It forms the upper margin of the fenestra ovalis, and is 
especially related to the anterior vertical semicircular canal. It is 
called the Pro-otic. We have next one (6) which gives rise to the 
lower part of the petrosal (that concealed by the auditory bulla), 
which forms the lower part of the fenestra ovalis, and surrounds 
entirely the fenestra rotunda. It is called the opisthotic. Lastly, 
we have an ossification (7) which gives rise to the mastoid process, 
and which is developed upon the hinder part of what will be here- 
after described as the posterior vertical semicircular canal of the 
internal ear. This ossification is named the epiotic. The whole of 
these, i. e., the petrous and mastoid portions taken together, are 
known as the " periotic." The temporal bone articulates with the 
occipital behind, with the parietal above, in front, with the 
sphenoid, and (through the zygomatic process) with the malar. 
The apex of the petrosal is wedged in between the basi- occipital and 
the sphenoid. 

§ 27. The sphenoid is also a very complex bone, and consists of 
two distinct parts,* one anterior, the other posterior. The posterior 
sphenoid may be first described. This is the central bone of the 
base of the skull, and its median part, or body, called the bast- 
sphenoid (bs), joins the basi-occipital behind. It has on the middle 
of its upper surface a shallow pit called the sella tardea, or pituitary 
fossa, because it receives and supports an appendage of the brain, 
called the " pituitary body.'* This fossa is bounded behind by a 
small plate of bone (cp), w 7 hich is inclined forwards as well as 
upwards, and the hinder surface of which is continuous with the 
upper surface (or basilar groove) of the basi-occipital. The plate is 
called the clinoid plate, and its two upper angles are produced 
outwards into prominences termed the posterior clinoid processes. 
Beneath, the basi-sphenoid is nearly flat, and becomes narrower as 
it advances forwards. Its structure is solid, not containing air- 
cavities. 

On each side of the basi-sphenoid there projects outwards a large, 
crescentic plate of bone, concave above from behind forwards (as), 
which is its longest dimension. This is the ali-sjihenoid, or great w r ing 
of the sphenoid, and it forms the side wall of the cranium, imme- 
diately in front of the squamosal and auditory bulla. Its upper 
margin is concave, the lower margin of the squama of the temporal 
bone being received into its concavity. Its hinder end overlaps the 
petrosal (helping to close the large aperture in which the Eustachian 
tube ends), and meets the anterior end of the ossified tentorial plate 
of the parietal. Its anterior end ascends behind the frontal, towards 
or to, the parietal. The ali-sphenoid is perforated on each side 

* It is described here as a single bone, because it is so considered in human 
anatomy. 



70 THE CAT. [chap. hi. 

by two foramina. The hinder and outer of these, which is the 
larger, is the foramen ovale (9), and transmits the third division of 
the fifth nerve. Immediately in front of this is a smaller opening, 
the foramen rotundum (8), which transmits the second division of 
the fifth nerve. Immediately in front of this again is a large and 
deep notch which, in the complete skull, is bounded in front by the 
hinder margin of the anterior sphenoid, and so is converted into a 
foramen. This aperture is called the sphenoidal fissure. It transmits 
the first division of the fifth nerve, together with the nerves of the 
orbit to be hereafter described. The upper surface of the posterior 
sphenoid exhibits, on each side of the sella, a faintly -marked groove 
(for a cranial artery) ending posteriorly in a notch. The piece of 
bone immediately external to such groove and notch (between the 
basi-sphenoid and the greater part of the ali-sphenoid) is called the 
lingula sphenoidalis, and is at one time of life distinct. 

Extending forwards much in front of the basi or ali-sphenoids 
are two complex bony plates which extend forwards and downwards 
from the junction of the basi- and ali-sphenoid on each side, and also 
join the palatine bones in front. Each of these is termed a pterygoid 
plate (pt) and its flattened upper surface articulates with the under 
surface of the anterior sphenoid. The under surface of this flattened 
part forms part of the basis cranii, and towards its outer margin a 
lamellar process of bone projects downwards., having at its hinder 
end a curved sharp-pointed process (the hamular process) arching 
backwards and somewhat downwards and outwards. Externally 
to this hamular process, the pterygoid plate sends outwards another 
small, more or less lamellar process. The very small space in- 
cluded between this last and the hamular process, is called the 
pterygoid fossa (pf), and there is of course one on each side of 
the skull. The very considerable space included between the two 
pterygoid plates is called the meso- pterygoid fossa, and that is single 
and median. The part which immediately supports and forms each 
hamular process, is originally a distinct bone, called the pterygoid bone. 

The anterior sphenoid is much longer in proportion to its width than 
is the posterior, but like it consists of a median part with two wings 
or lateral expansions. The median part, called the pre-sphenoid (ps)> 
joins the basi-sphenoid behind. It is not solid, but contains a great 
air-cavity, divided by a median septum into two " sphenoidal sinuses" 
which open widely at their anterior end (the bone expanding 
anteriorly into two ethmoidal processes (/;) ), to embrace the lower 
posterior angle of the ethmoid. The pre-sphenoid bears a median 
inferior ridge, the rostrum (r), which is visible between the inner 
margins of the two pterygoid plates of the posterior sphenoid. The 
upper surface of the vomer is attached to the anterior part of the 
rostrum. The upper surface of the pre-sphenoid is much elongated. 
Its anterior two thirds support the olfactory lobes of the brain and 
are convex from before backwards, but slightly concave from side to 
side. Its posterior third (separated from the more anterior part by 
two foramina) is slightly convex, and supports the optic nerves (where 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 71 

they unite in a commissure) on what is termed the olivary eminence. 
This eminence bounds anteriorly the pituitary fossa, and at each 
side of its hinder margin a minute process is to be detected. These 
are the anterior clinoid processes (ac). On (ach side of the pre- 
sphenoid there projects upwards and uitwards a short triangular 
plate of bone (os) called the orbital wing of the sphenoid, or orbito- 
sphenoid. This is pierced at its root by a considerable opening (7), 
the optic foramen, which transmits the n. rve of sight. The orbito- 
sphenoids form the anterior lateral part of the floor of the cranium, 
projecting upwards and outwards between the frontal in front, and 
the ali- sphenoid behind. 

The optic foramen opens immediately in front of, and al ove, the 
sphenoidal fissure and the round and oval foramina, all of which 
open into the bottom and hinder part of the orbital and temporal 
fossae (see Fig. 46, 6 , 7 , 8 , and 9 ). 

The sphenoid considered as one whole unites with thebasi-occipital, 
temporal, and parietal bones behind ; in iront, with the ethmoid, 
frontals, vomer, and palatines. 

§ 28. The ethmoid, or sieve-like bone — formed of very delicate 
lamellae very much contorted — is an exceedingly complex structure 
which tills up the spice (incisnra ethmoidalis) left between ihe con- 
stricted parts of the two frontals, and thence extends ( ownwards and 
forwards into the upp^r parts of the nasal chamber, which it almost 
entirely occupies. It is thus placed between the cranium and the 
face, extending forwards between the orbits and forming the hinder 
wall of the nasal cavity. It consists of a median and two lateral 
portions. The middle part is a simple vertical lamella of bone — the 
mesethmcid(Fig. 49, we), which extends forwards from the middle of the 
anterior surface of another transversely extended, obliquely ascending 
plate called, from the number of its foramina, *' cribriform. " From 
each side of the anterior surface of this cribriform plate (and on each 
side, therefore, of the mesethmoid), a mass of delicate and excessively 
plicated osseous tissue extends forward, bearing the name of the 
lateral ethmoid or eihmo-turbinal (Figs. 49 and 50, et). The meseth- 
moid has a free margin on every side except where it is anchylosed 
to the cribriform plate behind. Its superior margin is adjacent to 
the lower margin of the median deflected | ortion of the frontal, and 
to the inferior margin of the nasal. Its inferior margin dips down 
between the ascending bifurcating lamellae of tie vomer. The 
mesethmoid is much longer from before backwards than it is high. 

The ethmo-ttjtibinal rises (Fig. 50, et) on each side considerably 
higher than the upper margin of the mesethmoid, and into the 
chamber formed by the nasal and nasal process of the frontal on 
the inner side, and the preorbital process of the frontal on its outer 
side. It also descends slightly below the inferior margin of the 
mesethmoid, and joins the ascending, diverging, superior, and 
posterior part of the vomer. 

The folds and grooves of the ethmo-turbinal or lateral ethmoid 
proceed forwards and slightly downwards and outwards. 



72 



THE CAT. 



[chap. III. 



Close to the upper margin of the anterior lateral aspect of the 
lateral ethmoid is a small smooth, nearly triangular, surface, which 
appears on the inner wall of the orbit between the lachrymal, the 
frontal, and the palatine. It is called the os planum ; the lamellae 
which spring from the cribriform plate are also connected with the 
os planum. 

§ 29. The anterior inferior portion of the ethmoid mass (Figs. 49 
and 50, mt) is really a separate bone, called maxillo-turbinal. This 
consists of other plicated delicate lamellae which proceed from the 
inner surface of the maxilla. The grooves and folds of this mass 
of lamellae all proceed upwards and forwards. 

The passage between this maxillo-turbinal and the upper surface 





The Right Maxilla. 



A. External aspect. 

B. Internal aspect, 
m. Malar process. 
%. Nasal process. 



o. Sutural ridge. 

t. Tuberosity. 

2. Infra-orbital foramen. 



of the roof of the mouth is called the inferior meatus of the nose. 
The passage between this and the maxillo-turbinal, and the ethmo- 
turbinal, is called the middle meatus of the nose. 

A passage which traverses the ethmo-turbinal on a line with the 
inferior margin of the nasal bones is called the superior meatus of 
the nose. 

The mass of the ethmoid lies between the nasals and frontals 
above ; the orbital plate on the frontal, the presphenoid, the 
palatine, and the lachrymal on each side, and by the presphenoid, 
the vomer, and the palatines below. 



THE BONES OF THE FACE. 

§ 30. Having described those bones which enter into the com- 
position of the brain-case, it remains to describe those of the face, 
namely, the maxillary and pre-maxillary bones, the nasals, the 
malars, the lachrymals, the palatines, the vomer, the mandible, and 
the hyoid bone. The turbinal bones or maxillo-turbinals have 
already been noticed in describing the ethmoid, of which they seem 
to form the anterior, inferior portion. 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 73 

The maxillary bone, or maxilla, is the largest bone of the face, 
forming as it does, with its fellow of the opposite side, the main 
part of the upper jaw, and supporting all the upper teeth, except 
the incisors. It also contributes to form the cheek, the orbit, the 
nasal passage, and the palate. The two maxillary bones do not 
meet in the middle line below the anterior nares, but each sends up 
a prolongation — the nasal process — (n) to the frontal. This process 
bounds the inner side of the orbit anteriorly, and by its anterior 
and upper margin joins the nasal bone. Its inner surface exhibits 
a vertical groove, which is made into a canal by the help of the 
lachrymal bone. There is also on the inner surface a more or less 
horizontal ridge which serves to give attachment to the maxillo- 
turbinal. The superior, external part of the maxilla sends a process 
outwards (beneath the orbit), which joins the malar bone, and is 
therefore called the malar process (m). Superiorly the maxilla 
exhibits a smooth, horizontal surface (Fig. 28, m) which forms the 
floor of the orbit, and is called the orbital plate. It is traversed, 
from before backwards, by a groove ending anteriorly in a large 
foramen (2), which transmits the second branch of the fifth nerve, 
and is called the infra-orbital fifth nerve. 

On the outer surface of the maxilla, in front of the malar process, 
is a slight concavity termed the " canine fossa" Behind the malar 
process the outer surface of the maxilla has a slightly enlarged 
portion called the tuberosity (t), which is perforated by small 
foramina for the superior dental nerves and arteries. The lowest 
part of the maxilla is termed the alveolar border, and is hollowed 
out into the alveoli, or sockets, for the teeth. From this border the 
maxilla sends inwards a large horizontal process called the palatine 
plate. This is smooth and transversely concave above, but more or 
less roughened and grooved below. It rises somewhat where it 
meets its fellow of the opposite side in a sutural ridge (o), which 
supports the vomer. The anterior margin of the palatine plate is 
slightly, its posterior margin is deeply, concave. 

The maxilla articulates with the pre-maxilla and nasal in front, 
with the frontal above, and with the lachrymal, malar, and palatine 
behind. 

§ 31. The pre-maxilla is a very small bone placed in front of 
the maxilla, and joining, anteriorly, its fellow of the opposite side — 
the two together forming the anterior termination of the upper 
jaw. Each pre-maxilla consists of two unequal pointed processes 
diverging, one upwards and one backwards, from a thickened 
anterior portion which is the alveolar margin, and supports three 
incisors. 

The ascending, and much the larger, process (in) mounts up in 
front of, and adjacent to, the anterior margin of the ascending nasal 
process of the maxilla as far as the nasal, insinuating itself between 
that bone and the maxilla. The two pre-maxillae bound the anterior 
nares below and on each side, the nasals bounding the anterior nasal 
opening above. 



74 



THE CAT 



[CHAP. III. 





Fig. 39. — Right Pre-maxilla 

A. Inner aspect. 

B. Ventral aspect. 



to. Ascending process. 
p. Palatine process. 




From the inner side of the pre-maxilla the slender second or 
palatine process (p) extends backwards, in contiguity with its fellow 
of the opposite side, till it meets the anterior margin of the palatine 

plate of the maxilla. A 
B ~~ /in notch is thus formed be- 

A \X tween this backwardly ex- 

tending process and the 
more external portion of 
the pre-maxilla, and this 
notch is converted into a 
foramen by the palatine 
plate of the maxilla behind 
it. This is the anterior pala- 
?, or incisor foramen, which is the anterior termination of the 
anterior palatine canal transmitting the naso-palatine nerve. 

§ 33. The malar is a rather small, lamellar bone which forms the 

most prominent part of the cheek, 
the outer inferior margin of the orbit, 
and the anterior part of the zygoma. 
It is in the form of a curved 
quadrangular plate, convex without, 
concave within, and with certain 
processes. Its anterior inferior 
margin (m) rests on the malar pro- 
cess of the maxilla. Its anterior 
superior margin forms part of the 
rim of the orbit. Its posterior 
portion, or zygomatic process (z) is 
applied beneath the lower border 
of the zygomatic process of the 
squamosal. Immediately in front 
of the anterior end of that process 
the malar developes a post-orbital 
process (p) which mounts upwards, 
backwards, and inwards, towards 
but not to, the post- orbital process 
of the frontal. The poster o-inferior 
margin of the malar is strongly concave. 

§ 33. The nasals are two elongated, small triangular bones 
placed side by side above the anterior nares in front of the frontals. 
Ea^h is considerably extended vertically towards its hinder end 
(B and C), and somewhat less extended transversely towards its 
distal end (A). Its anterior margin is concave, its external angle {a) 
being produced forwards much beyond its internal angle. 

The inner side of the vertically- expanded part of the bone (B) is 
flat, and applied to its fellow of the opposite side. Its outer surface (0) 
is concave, and receives the nasal process of the frontal in a fossa 
specially destined for it (n). The nasals join the frontals, maxillae, 
and pre-maxillse, and form the superior margin of the anterior nares. 




Fig. 40.— Right Malar. 

A. External view. 

B. Internal view. 

to. Surface for malar. 
p. Post-orbital process. 
z. Zygomatic process. 



chap, in.] SKELETON OF TEE HEAD AND TRUNK. 



75 



§ 34. The lachrymals are also very small bones, one of which, 
is placed at the anterior part of the inner wall of each orbit (Fig. 46, 
la), having the frontal above, the os planum behind, the nasal pro- 






Fig. 41. — Right Nasal. 

A. External surface. 

B. Surface turned towards the other nasal 
C Outer lateral surface. 

a External angle. 

n. Fossa for nasal process of maxilla. 




Fig. 42.— Right Lachrymal. 

A. Outer surface. 

B. Inner surface. 



cess of the maxilla in front, and the orbital plate of the same bone 
below. Each lachrymal is marked by a vertical groove and notch (n), 
which, by joining the similarly directed groove on the posterior side 
of the nasal process of the maxilla, forms a foramen and canal, 
called " lachrymal," which leads from the orbit to the nasal cavity. 

§ 35. The palatines are two bones which by their median 
junction behind the maxillae, complete the bony palate, which, as 
we have already seen, is partly formed by the palatine plates of the 






Fig. 43.— Right Palatine Bone. 



A. Ventral aspect. 

B. Cranial, or dorsal aspect. 
C Anterior aspect. 

a. Ascending plate. 



h. Horizontal plate. 
3. Palatine foramen. 
5. The spheno-palatine foramen. 



maxillae. The palatine is irregular in shape, consisting mainly of 
two unequal plates, which are inclined inwards towards each other 
at an acute angle — one ascending, one horizontal. The bone is 
wedged in between the maxilla in front and the pterygoid behind. 
It bounds the meso-pterygoid fossa laterally, and the hinder part of 
the nasal cavity inferiorly ; and it forms part of the floor and of the 
inner wall of the crbit. 

The ascending plate (a), which is the main portion of the bone, is 



76 THE CAT. [chap. hi. 

more than twice as long as it is high. ; hut its anterior half is higher 
than its posterior, and presents two foramina, one of very considerable 
size, the spheno -palatine, foramen directly over a very much smaller 
posterior palatine foramen (Fig. 43, B). More than the hinder half 
of the inferior margin of this ascending plate is smooth, free, and 
concave ; the rest of that margin joins the maxilla. Its hinder end 
joins the pterygoid. The hinder half of its superior margin joins the 
orbito-sphenoid and the pre-sphenoid, to which latter the concavity 
its of upper margin is adjusted. Its more anterior portion is applied 
against the outer side of the ethmo-turbinal. The horizontal 
lamella (Ji) projects inwards (from the anterior two-thirds of the 
inferior margin of the ascending lamella), and joins its fellow of the 
opposite side in the middle line, and there also joins the inferior 
margin of the hinder part of the vomer. Its anterior margin is 
convex, and adjoins the hinder margin of the palatine plate of the 
maxilla of the same side. Its hinder margin is concave and free, 
forming the posterior limit of the bony palate and the anterior 
boundary of the meso-pterygoid fossa. The posterior palatine 
foramen (3) very near to, or at, its anterior margin. 

The palatine articulates with the maxilla, the vomer, the lachry- 
mal, the os planum, the orbital plate of the frontal, the pre-sphenoid, 
and the orbito-sphenoid. 

§ 36. The vomer (Fig. 49, v) is a single, thin, median bone 
grooved above, and extending down vertically from the basi-sphenoid 




an 

Fig. 44.— Inside of Right Half of Mandible. 

an. Angle, 
c. Coronoid process. 
ar. Ascending ramus. 
hr. Horizontal ramus. 



sy. Symphysis. 

y. Condyle. 

14. Inferior dental foramen. 



and ethmoid, to the upper surface of the bony palate, thus completing 
a vertical median partition between the nostrils. It is a very 
long and narrow bone, very obliquely quadrangular in shape. Its 
hinder portion, however, expands horizontally, to support and unite 
with the inferior and hinder parts of the ethmo-turbinals — its hinder 
end under-lapping the anterior part of the pre-sphenoid. In front 
of the expanded part, the grooved upper surface of the vomer 
receives within its groove the lower edge of the mesethmoid ; while, 
still more anteriorly, the septal cartilage of the nose is received 
within the. same groove. The lower margin of the vomer unites 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 77 

with, the palatine plates of the maxillae and palatines. Its posterior 
margin is free, and forms the hinder end of the lower part of the 
internasal septum. 

§ 37. The skeleton of the lower jaw, or mandible, consists of 
two bones, which meet together in front at an acute angle. Each 
bone, ie. f each half of the mandible, consists of two parts — its hinder, 
vertically expanded portion, being called the ascending ramus (ar), 
while the rest is named the horizontal ramus (hr). The horizontal 
ramus is almost of the same depth throughout, and slightly curved — 
its upper margin being concave, and its lower margin convex. The 
latter is smooth and rounded, but the upper edge is festooned by 
unequal cavities, forming sockets for the lower teeth. The place of 
junction of the two horizontal rami is called the symphysis (sy), and 
presents a very rough surface. The horizontal ramus begins to 
expand into the ascending ramus immediately behind the last tooth, 
and becomes a triangular plate of bone, concave externally, and 
with three prominences, separated by two concavities, on its hinder 
margin. 

The highest of these prominences (which is also the highest part 
of the mandible) is called the coronoid process, and is a vertical pla/te 
of bone (c). The second prominence (separated from the preceding 
by a considerable interval) is the condyle of the mandible, and is a 
transversely- extended convex articular surface (y), destined to fit 
into the glenoid fossa of the temporal bone. The piece of bone 
which immediately supports the condyle is termed the neck. The 
third and lowest prominence (separated from the condyle but by a 
narrow interval) is termed the angle (an), and is a small, vertically- 
extended process, on a line with the inferior margin of the horizontal 
ramus. 

The coronoid process rises even a little more above the condyle 
than does the latter above the angle, and has inserted into it the 
temporal muscle. 

The deep fossa outside the ascending ramus (Fig. 46, ar), the 
ridge beneath it and the angle, have inserted into them a muscle, 
called the masseter. The symphysis is convex and very oblique, 
being inclined strongly backwards as well as downwards. 

The outer surface of the horizontal ramus is convex, its inner 
surface is flattened. On the inner side of the ascending ramus, 
below the level of the condyle, is a considerable foramen, called the 
inferior dental (14). This leads into the " dental canal," down which 
the dental nerves and vessels pass. 

At the more anterior part of the outer side of the horizontal ramus 
are a pair of small foramina (Fig. 46, 13 ), called the mental foramina. 
They transmit branches of the inferior dental nerve and artery. 

Behind the symphysis, towards its lower end, is a small depression 
serving for the insertion of the digastric muscle. 

§ 38. The hyoid apparatus is a complex structure, consisting of 
two long jointed bony bars (t* to ch), "the anterior cornua," and 
two short unjointed bony bars (th), " the posterior cornua " — both an 



73 



TEE CAT. 



[CHAP. III. 



anterior and a posterior cornu springing from either end of a median 
bony bar, " the body of the hyoid" (bh)> or basi-hyal. The basi-hyal 
is a transversely- extended flattened bar of bone, which, in the 
natural condition, is placed above the front part of the thyroid 
cartilage of the larynx (T). At the front margin of each end is 
attached a short cylindrical bone (about half the length of the basi- 
hyal), called the cerato-hyal {ch). To the end of this, is again 
annexed another long bone, called the epihyal (eh), at the end 





Fig. 45. — Hyoid Appaeatus, with Larynx and upper part of Trachea. 



A. Ventral view. 

B. Lateral view. 

a. Connexion of thyrohyal with thyroid carti- 
lage. 
th. Basi-hyal. 
ch. Cerato-hyal. 
ct. Cri co-thyroid mnscle. 
eh. Epihyal. 

s. Sterno-hyoid muscle cut short. 
st. Sterno-thyroid muscle cut short. 



t*. Cartilage of tympano-hyal. 

th. Thyro-hyal. 

ty. Thyro-hyoid muscle. 

tr. Trachea. 

p. Crico-thyroid ligament. 

C. Cricoid cartilage. 

T. Thyroid cartilage. 

1. Thyro-hyoid membrane. 

2. Crico-thyroid membrane. 



of which is another cylindrical bone, called the stylo-hyal (sh), 
which is again longer than the epihyal. At the end of the stylo- 
hyal is a cylindrical cartilage (t*), which is the cartilaginous con- 
tinuation of that minute cylindrical bone, the tympano-hyal, which 
becomes anchylosed into the pit before noticed as existing in the 
auditory bulla immediately on the inner side of the stylo-mastoid 
foramen. 

This chain of ossicles, with its fellow of the opposite side, together 
constitute the anterior cornua. (See also Fig. 46.) 

At the hinder margin of each end of the basi-hyal (just below the 
attachment of the cerato-hyal) is a cylindrical bone attached, called 
the thyro-hyal (th). This is about as long as the basi-hyal, and 
shorter than the stylo-hyal. It is connected by membrane with the 
upper border of the lateral part of the thyroid cartilage of the larynx. 

§ 39. On examining in greater detail than heretofore, and with that 
knowledge of its component bones which the foregoing pages may have 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 79 

afforded, we find, when the outside of the skull is viewed in front, 
(Fig. 30) the following parts : — Below, the maxillae and pre-maxillse 
form the alveolar borders. The curved outline of the vertex (/) is 
formed by the frontals. The two large and conspicuous orbits are 
bounded below by the zygomata, from which the malar post-orbital 
processes (pj) ascend, and approach the descending (pf) post-orbital 
processes of the frontals. Between the orbits there is a broadish 
bony expanse (formed by the frontals, nasals, and maxillae), except 
inferiorly where the heart-shaped aperture of the anterior nares is 
situated — only bounded below by the horizontal processes of the 
pre-maxillae (pm). The nasal bones (n) ascend rather higher than 
do the nasal processes of the maxillae. On each side of the anterior 
nasal opening, and just beneath the margin of the lower boundary 
of the orbit, is the large opening of the infra-orbital canal (2). 

The parts which project furthest outwards are the zygomatic 
processes of the temporal bones (s). 

At the back of each orbit is seen the convex side-wall of the 
skull (/) projecting into it, but the foramina which open into the 
bottom of the orbit are hidden from this point of view. 

On examining the base of the skull (see Fig. 29), we find in 
front the alveolar margin (describing an acute but truncated angle, 
with its truncated apex forwards) surrounding the bony palate (m 
and p), which extends a little farther backwards than do the teeth. 
The anterior end of the bony palate is formed by the pre-maxillae (pm), 
between which and the maxillae are the two large anterior palatine 
foramina. At above the place of junction of the palatine plates of 
the maxillae with the palatines, there are on each side one or two 
much smaller foramina, termed the posterior palatine foramina (3). 

Behind the palate, we have, in the middle, the meso-pterygoid 
fossa (ps) (into which the posterior nares open), bounded laterally 
by the palatines and pterygoids {pf). External to this, is on each, 
side the wide vacant space of the temporal fossa enclosed by the 
zygoma. 

Behind the meso-pterygoid fossa the basis cranii presents a 
straight surface of about equal width, formed successively by the 
under surfaces of the basi-sphenoid (bs) and basi-occipital (bo), and 
terminated posteriorly by the occipital condyles (pc) and foramen 
magnum (fm). At the hinder and outer side of each pterygoid 
bone is the minute pterygoid fossa, external to, and partly hidden by, 
the hinder part of which is the foramen rotundum (8) ; while the 
foramen ovale (9) is again just behind, and external to, the foramen 
rotundum. External to the foramen ovale, and on a line with it, is 
the glenoid fossa for the lower jaw (g), bounded posteriorly by the 
post-glenoid process behind, and internal to which is the fissura 
Glaseri. Behind this again, is the large and swollen auditory 
bulla (b), at the anterior end of which, immediately behind the 
foramen ovale, is the anterior aperture of the Eustachian tube (10), 
and a very small aperture called the foramen lacerum anterius, lead- 
ing into the inside of the cranium. Between the inner hinder part 



80 



THE CAT. 



[CHAP. III. 



of the auditory bullae and the basi- occipital is the large and con- 
spicuous foramen lacerum posterius (11), which transmits the jugular 
vein and the glosso -pharyngeal, par vagum and spinal accessory 




Fig. 46.— Side view of the Cranium, the Lower Jaw and the Hyoidean Arch 

BEING SOMEWHAT DETACHED. 



a. (Just above 6 and 7). Ali-sphenoid. 


pa. Palatine. 


ae. Meatus auditorius externus. 


pt. Pterygoid. 


an. Angle of mandible. 


pm. Pre-maxilla. 


ar. Ascending ramus. 


s. Squamosal. 


b. Auditory bulla. 


sh. Stylo-hyal. 


bh. Basi-hyal. 


so. Supra-occipital. 


c. (Of cranium) occipital condyle. 


t*. Cartilage of tympano-hyal. 


c. (Of mandible) coronoid process. 


th. Pit of tympano-hyal. 


ch. Cerato-hyal. 


y. Apex of lambdoidal ridge. 


eh. Epi-hval. 


z. Zygoma. 


f. Frontal. 


2. Infra-orbital foramen. 


hr. Horizontal ramus of mandible. 


6. Optic. 


ip. Inter-parietal. 


7. Sphenoidal fissure. 


;. Malar (or jugal). 


8. Foramen rotunclans. 


la. Lachrymal. 


9. Foramen ovale. 


m. Maxilla (its nasal process). 


12. Stylo-mastoid foramen. 


wis. Mastoid process. 


13. Mental foramina. 


Ify Nasal. 


The spheno-palatine foramen is shown just 


Os. Orbito-sphenoid. 


above, and in front of fa, close to posterior 


p. Parietal. 


margin of anterior end of zygoma. 



nerves. This foramen is bounded behind by the exoccipital (pp), 
which is perforated by the anterior condyloid foramen transmitting 
the hypoglossal nerve. At the anterior wall of the foramen lacerum 
posterius is the opening of a very small canal (for the minute 
internal carotid artery) which runs forwards (between the basi- 
occipital and basi-sphenoid on one side, and its auditory bulla 
on the other) to open inside the cranium beside the sella turcica. 



CHAP. III.] 



SKELETON OF THE HEAD AND TRUNK. 



81 



Behind the post-glenoid process, the large meatus auditorius externus 
is to be seen, and close behind it the stylo-mastoid foramen (12), 
immediately internal to which is the pit for the tympano-hyal, 
in close contiguity to which again the small mastoid process is seen 
descending (ms). 

Looking at the side of the skull, we see above, the evenly- 
arched outline of the cranium and face (formed by the nasals, 
frontals, and parietals), with the straight but inclined line of the 
occiput behind. The base of the skull is almost straight, though 




Fig 47.— Skull viewed, from behind with the Lower Jaw detached. 



-a^- Angle of mandible. 

b. Auditory bulla. 
bo. Basi-occipital. 

c. Coronoid process of mandible. 
/ Condyle of mandible. 

fm. Foramen magnum. 
g. Glenoid surface. 
gp. Post-glenoid process. 
ip. Inter-parietal. 
I. Lambdoidal ridge. 
ms. Mastoid process. 



oc. Occipital condyle. 

p. Parietal. 

pf. Post-orbital process of frontal. 

pj. Post-orbital process of malar. 

so. Supra-occipital. 

sq. Squamosal. 

s. Zygoma. 

14. Inferior dental foramen. 

The par-occipital process is seen (on each side) 
between the occipital condyle {oc), and the 
auditory bulla (b), aud above the latter. 



the middle part does not descend so much as does the alveolar 
margin in front or the auditory bulla behind. The anterior end of 
the skull is formed by the small premaxilla (Fig. 46, pm), which 
ascends and joins the nasal (n). Behind this the wide nasal process of 
the maxilla (m) is interposed in front of the orbit, the anterior margin 
of which slopes upwards and backwards. Just inside the lower part 
of that margin is the lachrymal bone (la) with its foramen ; behind 
which is the os planum. The frontal (/), palatine, pre-sphenoid, and 
orbito-sphenoid (os), form the inner wall of the orbit. Just below 
the front part of the inferior margin of the orbit is the infra-orbital 
foramen (2). Behind, and on a level with this (within the orbit), 



82 THE CAT [chap. hi. 

are the spheno-palatine foramen and the posterior palatine canal. 
The orbit is seen to be bounded below by the maxilla, on which the 
malar (/) is imposed, and sends up its post-orbital process towards, 
but not to, the descending post-orbital process of the frontal. The 
lower margin of the malar is strongly concave, and the zygomatic 
process of the squamosal (z) is also strongly concave below, the 
zygoma being much arched upwards as well as outwards. 

At the bottom of the orbit we find, one behind the other, the 
optic foramen (6), sphenoidal fissure (7), round foramen (8), and 
the foramen ovale (9) : while the side wall of the cranium sends 
outwards a marked but blunt projection (formed principally by the 
ali-sphenoid), which runs upwards towards the post-orbital process of 
the frontal, and would, if it were greatly enlarged, more or less 
enclose the orbit posteriorly. 

Beneath, the hinder end of the zygoma, is the glenoid fossa 
and post-glenoid process ; and behind this, the auditory bulla (b), 
with its external meatus (ae), the stylo-mastoid foramen (12), the 
pit for the tympano-hyal (t) t and the mastoid (ms) and par-occipital 
processes. Thence, the lambdoidal ridge (y) runs upwards and 
backwards, while behind and beneath it we have the ex- and 
supra -occipitals (so), with the occipital condyle (c). 

If the skull be viewed from behind, we see extending beyond its 
globular mass (the upper walls of which are formed b}^ the parietals 
(Fig. 47, p) ) the zygoma, widely arching out on each side (s), 
the much smaller post-orbital processes of the frontal (pf) above, 
and the depending, rounded, auditory bullae (b) below. In the 
middle, between the bullae, there is the foramen magnum (fm), 
with the occipital condyle (oc) on each side of it. The bulla is seen 
to be clamped laterally and behind by the mastoid (ms) and par- 
occipital processes, which are closely applied to it. The foramen 
magnum is bounded above by the supra- occipital (so), on each side 
of which the lambdoidal ridge (I) runs up to the interparietal (ip). 

In the lower jaw we see the angle (a), the great transverse extent 
of the articular condyle (/), and the lofty coronoid process (c). 

If the skull be examined dorsally, the two large frontals and 
parietals will be seen separated by the crucial mark formed 
by the sagittal, frontal, and coronal sutures, while the maxillae, 
premaxillae, and nasals, are conspicuous in front (Fig. 28). The 
floor of the orbit is also well seen to be composed mainly of the 
maxilla (m), with the help of palatine (p) and lachrymal (/*) 
internally, and of the malar (j) externally. The posterior opening 
of the infra- orbital canal also comes into view as well as the 
posterior palatine foramen (4) and the spheno-palatine foramen (5). 
The inward curvatures of the post-orbital processes of the malars (pj), 
and the outward curvatures of the frontal post-orbital processes (pf) 
are also very marked from this point of view. 

In the inside of the cranium, as seen from above when a 
horizontal section is made and the top of the skull is removed, we 
may note the following conditions : — 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 83 

In the middle, in front, is a small fossa bounded anteriorly by the 
cribriform plate, and on each side by the orbital plates of the frontal. 
This is the olfactory, or rhinencephalic, fossa, which shelters the 
olfactory lobes of the brain. The hinder part of its floor is formed 
by the pre-sphenoid. 

Behind the olfactory fossa is the great middle fossa of the cranium, 
bounded posteriorly by the ossified tentorium, which is attached to 
the parietals and petrosals. In the middle of the floor of this great 
chamber is the pituitary fossa, or sella turcica (Fig. 49), situated on 
the upper surface of the basi-sphenoid. On each side of this (placed 
successively in series running backwards and outwards) are (1) the 
optic foramen (piercing the orbito-sphenoid) ; (2) the sphenoidal 
fissure (placed beside the anterior wall of the pituitary fossa) ; 
(3) the foramen rotundum ; and lastly (4) the oval foramen ; the 
latter being on a line with the hinder part of the pituitary fossa. 

External to this line of foramina on each side, there is a depression 
(on the upper surface of the aJi-sphenoid and squamosal) which is 
called the internal temporal fossa, because it shelters the temporal 
lobe of the brain. 

Behind the pituitary fossa is the clinoid plate, and behind and 
external to this on each side is an opening between the petrosal, 
the ali-sphenoid, and the anterior end of the tentorium, which 
opening communicates with the cavity of the auditory bulla and with 
the foramen lacerum anterius. 

Behind the clinoid plate and the tentorium, is the posterior fossa of 
the cranium — called also the cerebellar fossa, because it shelters that 
part of the brain called the cerebellum. The floor of this fossa is formed 
by the basi-occipital, and its sides by the ex-occipitals and petrosals. 

Between the basi-occipital and the adjacent petrosal there runs 
forwards on each side a very minute canal destined for the carotid 
artery. The surface of the petrosal exhibits the conspicuous 
opening to the internal ear — the meatus auditorius internus — with 
the fossa above it for a process of the cerebellum (Fig. 35, B, cb) f 
above and behind which again is the prominence indicating the 
anterior vertical semi-circular canal. 

Behind each foramen lacerum posterius, and separated from it 
by a narrow bridge of bone, is the anterior condyloid foramen. The 
inner surface of the sides and roof of the cranium is marked by wide 
and shallow depressions corresponding with eminences on the surface 
of the brain, and also with narrow meandering grooves indicating the 
course of the blood-vessels. 

The skull vertically bisected, in the direction of the sagittal 
suture, exposes the larger size of the brain cavity than of the part 
which forms the face ; also the inclined condition of the cribriform 
plate (Fig. 48, cp) and the more nearly vertical position of the foramen 
magnum at quite the hinder end of the skull. 

The basilar parts of the occipital and sphenoid bones (Fig. 49, bo, bs, 
and ps,) are seen to become thicker as we go forwards ; they form the 
true axis of the skull, and a line drawn from the anterior margin of 



84 THE CAT. [chap. hi. 

the foramen magnum to the front end of the middle part of the 




Fig. 48.— Outline of Vertical Section of Skull, to show bt straight black lines the 
inclination of the basi-facial axis to the basi-cranial axis, and the angles 
formed with the latter by the planes of the cribriform plate and occipital 
Foramen ; also the relative Cerebral Length. 



be. Basi-cranial axis. 

bf Basi-facial axis. 

c. Length from the front end of the basi-cranial 



axis to the summit of the attachment of the 

tentorium. 

cp. Plane of cribriform plate. 

fm. Plane of foramen magnum. 



upper (or cerebral) surface of the pre-sphenoid is called the basi- 
cranial axis (Fig. 48, be). A line drawn from the same point of the 




Fig. 49.— Vertical Antero-posterior Section of Skull, made a little nearer the 
Spectator than the exact middle line to show the Median Ethmoid, etc. 



af. Aqueduct of Fallopius. 

al. Internal auditory meatus. 

&. Auditory bulla. 

bo. Basi-occipital. 

c. Occipital condyle. 

el. Lateral ethmoid. 

/. Frontal. 

fm. Foramen magnum. 

ip. Inter-parietal. 

me. Mesethmoid. 

mt. Ethmo-turbinal. 



n. Nasal. 
ps. Pre-sphenoid. 
pt. Pterygoid, 
s. Squamosal. 
sq. Basi-sphenoid. 
so. Supra-occipital. 
t. Inner surface of frontal. 
v. Vomer. 

The anterior condyloid foramen above c 
and bo, just over the letter 6. 



pre-sphenoid to the front part of the alveolar margin of the pre- 



chap, in.] SKELETON OF TEE BEAD AND TRUNK. 85 

maxilla is the bast-facial axis (bf), and the two axes in the cat form 
an angle of 145°. 

The hasi- cranial axis forms with the foramen magnnm (fm) an 
angle of 110°, while with the cribriform plate (cp) it forms one of 
155° — open upwards and backwards. 

The extreme length of the line (c), slightly exceeds that of the 
basi-cranial axis (be), while it is itself somewhat exceeded by the 
cerebral length, i.e., the length between the front end of the olfactory 
fossa and the hind-most point of attachment of the tentorium. 

As to the details of the parts shown in a median vertical section, 
we see in the first place the large cerebral chamber (Fig. 49, s, t), in 
front of which is the more solid, facial part with the mesethmoid {me) 
interposed between the vomer (v) below and the inflected plates of 
the frontal and the nasal (/, n). 

The cerebral chamber is seen to be bounded behind by the bony 
tentorium descending as a free process from the hinder end of the 
parietal (p), and being attached to the inner anterior margin of the 
petrosal. In the petrosal we see the internal auditory opening (ai) 
in a fossa, from the anterior part of which (of) proceeds the aqueduct 
of Fallopius. Above and slightly behind this fossa, is seen that for 
the cerebellar process. We see also the concavity of the pituitary 
fossa in the upper surface of the basi-sphenoid (sg), with the large 
air- cavity in the pre-sphenoid (ps). In the ex-occipital we see the 
anterior condyloid foramen (for transmitting the hypoglossal nerve), 
with another foramen, for a vein, behind it. 

When the skull is cut vertically a little on one side of the antero- 
posterior median line we then see (Fig. 50) the frontal sinus (fs) 
extending backwards over the anterior part of the cranial cavity. 
We also see how the ethmo-turbinal, or lateral ethmoid, sends its 
lamellae quite upwards in front of the frontal sinus (the upper et), 
as well as horizontally forwards (the lower et of Fig. 50). We also 
see more plainly (than in the perfectly median vertical section) 
the contrast which exists between the direction followed by the folds 
and furrows of the ethmo-turbinal and that which the folds and 
furrows of the maxillo-turbinal (mt) follow. 

When the skull is divided vertically through the external auditory 
meati {i.e.,. transversely, or in the direction of the coronal suture) we 
see that the basilar part of the occipital forms as it were a centre. 

The anterior part of such a section shows the great cranial arch 
rising above this centre and closed in front, while below it, is the 
arch of the lower jaw and farther forward the arch of the upper 
jaw — enclosing the double tube of the nostrils, which extends from 
the anterior to the posterior nares. 

The posterior part of the section shows us the hinder part of the 
great cranial arch rising above around the foramen magnum 
behind, while below it, is the arch of the hyoid extending downwards 
on each side from the tympano-hyals to the basi-hyal. 

As to the cavities of the skull : the two orbits are separated 
one from another in part by the cranial cavity (behind the cribri- 



86 THE CAT. [chap, iil 

form plate), and in part by the nasal cavity (in front of the 
cribriform plate). 

The nasal fossce extend backwards, above the palate, from the 
anterior to the posterior nares, and are enclosed between the pre- 
maxillae, maxillae, and palatines, being separated from each other 
by the median ethmoid and vomer, and, in front of these, by a 
median cartilage of the nose called " septal." The lateral ethmoid 
projects forwards into each fossa from the cribriform plate (cp). 

The roof of the nasal cavity slopes downwards both anteriorly 




Fig. 50. — Longitudinal Vertical Section of Face made a little further off 

THAN THE MIDDLE LINE. 



cp. Cribriform plate. 

et. Lateral ethmoid or ethmo-turbmal. 

Js. Frontal sinus. 

int. Maxillo-turbinal. 

m. Maxilla. 



p. Palatine. 
pm. Pre-maxilla. 
ps. Pre-sphenoid. 
pt. Pterygoid. 



and posteriorly. Its floor is formed by the palatal plates of the 
maxillae and palatines, and is pierced, towards its anterior end, by 
the anterior palatine foramina. 

The spheno-palatine foramen opens into the nasal cavity on each 
side towards the hinder end very near its floor. 

The bones of the cranial vault are densest at the surface, beneath 
which is a coarser, spongy bone-tissue termed " cliploe." Here and 
there are much larger cavities, which are filled with air, and are 
termed sinuses. Of such there are two sets. 

The first of these, the frontal sinuses, are in the substance of the 
frontals (fs), and they communicate with the nasal fossae. The 
other set, the sphenoidal sinuses, are situated in the pre-sphenoid, 
and are smaller than the frontal sinuses (Fig. 49, ps\. 

§ 40. Besides the ligaments of the skull already noticed — those 
connecting it with the vertebral column — other ligaments connect 
the mandible with the cranium. 

These may be described as the " capsular " and " stylo-maxillary n 
ligaments. 

The apposed surfaces of the mandibular condyle and glenoid 
cavity are, in the fresh condition, each coated with cartilage, and 



chap, in.] SKELETON OF THE HEAD AND TRUNK. 87 

two fibrocartilaginous disks (inter- articular fibro-cartilages) are inter- 
posed between the two articular surfaces. Motion is facilitated by- 
three separate synovial membranes ; one between the disks, one 
between the upper disk and the glenoid surface, and the third between 
the lower disk and the condyloid surface. 

The capsular ligament is a fibrous membrane which surrounds 
the articulation just mentioned, its fibres passing from the circum- 
ference of the glenoid surface to the condyle. It adheres to the 
margins of the interposed nbro-cartilaginous disks, and it is 
strengthened on its inner and outer sides by certain accessory fibres 
which might be distinguished respectively as internal and external 
lateral ligaments. 

The stylo-maxillary ligament arises mainly from behind, but 
partly from in front of the margin of the meatus auditorius externus. 
It passes to the angle of the mandible. 

It gives attachment, on its inner side, to some of the fibres of the 
internal pterygoid muscle. The stylo-glossus is attached to its 
upper surface, while its exterior is connected with the masseter. 

A thin inter articular cartilage is interposed between the anterior 
margins of the two horizontal rami of the mandible. 

Another cranial ligament which it may be well to mention, is 
the post-orbital ligament which connects the apex of the post : orbital 
process of the malar with the apex of the adjacent post-orbital 
process of the frontal. 

§ 41. Having now completed our survey of the parts which make 
up the cranial division of the cat's axial endo-skeleton, the most 
generalized view of them at present attainable may, perhaps, be 
expressed as follows : — 

The skull consists of a central axis, made up of the basi- occipital, 
basi-sphenoid, and pre-sphenoid, and which axis is continued on 
forwards by the median ethmoid. 

To this central axis ascending and descending arches are annexed, 
having certain other structures intercalated between the former. 
Thus we have an occipital arch completed by the basi- occipital, 
ex-occipitals, and supra- occipital. 

Secondly, we have a posterior sphenoidal arch, completed by the 
ali-sphenoids and parietals. 

Thirdly, we have an anterior sphenoidal arch, completed by the 
orbito-sphenoids and the frontals. These three arches embrace the 
brain, which is the enlarged anterior continuation of the spinal 
marrow and forms the anterior termination of the nervous centres. 
On this account these arches may be termed " neural," like the 
vertebral arches which similarly enclose the spinal marrow. 

The most anterior, or anterior sphenoidal arch, is open in front, 
the bone of the olfactory organ (the ethmoid) being, as it were, 
thrust into the aperture which is left by it. 

Into the gap left on each side between the ex-occipital and the 
ali-sphenoid, the auditory organ (the temporal bone) is thrust. 

Similarly, the very much smaller gap left between the ali- and 



88 TEE CAT. [chap. hi. 

orbito-sphenoids (which is indeed only represented by a large foramen 
and the sphenoidal fissure) is filled up by the organ of sight, which, 
though not ossified in the cat (as the olfactory and auditory organs 
are), is protected by bony processes about it. 

Beneath the basis cranii .we have : — (1) the thyro-hyals, which 
send up no connecting ligaments to the skull, but which through 
the basi-hyal are connected, by the epi- and cerato- stylo -hyals with 
the tympano-hyals. (2). In front of this hyoidean arch we have 
the mandibular arch, and (3) again in front of this we have an 
arch formed by the pterygoid and palatines, and bordered externally 
by the maxillae and pre-maxillse. This last arch is amalgamated 
with the bony covering of the nostrils (the nasals) and with the 
outer protection of the orbits (the malars), which latter send back, 
on each side, a bony arch (the zygoma) to the ossified envelope of 
the auditory organ. 

Thus we seem to find in the cranial part of the axial skeleton, a 
sort of reminiscence of the structure of the parts composing its spinal 
portion. 

From median axial structures which seem to repeat the vertebral 
centra, neural arches arise and ventral girdles descend, which arches 
and girdles seem to repeat, on a different scale, the neural and rib 
arches of the trunk. 



CHAPTEE IV. 

THE SKELETON OF THE LIMBS. 

1. The skeleton of the limbs, or appendicular skeleton, is divisible 
into the skeleton of the anterior, thoracic or pectoral limbs, and that 
of the posterior abdominal or pelvic limbs. 

THE SKELETON OF THE PECTORAL LIMB. 

The bones of the cat's pectoral limb belong to three categories : 
A. those of the shoulder ; B. those of the fore-leg ; and C. those of 
the paw. 

A. Those of the shoulder are the blade-bone, called the scapula, 
and the collar-bone, called the clavicle. These, with their 
fellows of the opposite side, constitute what is called the 
shoulder- girdle. 

B. Those of the fore-leg are subdivisible into (a) the bone of the 
part above the elbow, called the humerus, and (b) the bones of the 
part below the elbow, called respectively the radius and the ulna. 

C. Those of the paw are divisible into three sets : (a) the bones 
of the wrist, called in anatomy the carpus; (b) those of the 
middle solid part of the paw, called the metacarpus ; and 
(c) those of the toes (or digits), which are called phalanges. 

§ 2. The scapula is a flat, somewhat triangular bone, with three 
borders and two surfaces. One border is anterior, one is superior, 
and one is posterior. The superior border (Fig. 51, v) is also called 
" vertebral," because it is the one nearest to the vertebral column. 
The posterior border (x) is also called "axillary," because it is 
adjacent to the axilla, or arm-pit. Of its surfaces, one is applied 
against the ribs, and is concave ; it is called the subscapular fossa, 
and affords attachment to the subscapularis muscle. It presents one 
or two oblique ridges. 

The other (dorsal or outer) surface is divided obliquely into two 
unequal parts by a prominent ridge, called the spine (s), on which 
account the smaller part in front of the ridge is termed the supra- 
spinous fossa (ss), and the part behind it (is) the infra-spinous fossa. 
These spaces are occupied by correspondingly named muscles. 

The spine of the scapula becomes gradually mare prominent from 
the vertebral border of the bone, while at its outer end the spine 



90 



THE CAT. 



[CHAP. IV. 



projects freely as a small process terminating in a rounded end, and 
called the acromion (a) ; but before so terminating, it gives off a 
backwardly directed lamellar freely projecting process termed the 
metacromion (m) . 

The anterior border of the scapula (which is rounded and convex) 
exhibits at its lower end a rounded notch (n). Below this notch 
there rises a short strongly projecting, much curved, pointed pro- 
minence, called the coracoid process (Fig. 52, c). 

The superior border of the scapula (v) is the shortest. It is very 
slightly convex. 

The axillary border is the longest, and is more or less grooved on 
its inner aspect (x). It descends obliquely from the lower end of 




Fig. 51.— Right Scapula, seen exteknally. 



a. Acromion. 

g. Glenoid surface. 

is. Infra-sTjinous fossa. 

m. Metacromion. 

n. Supra-scapular notch. 

s. Spine. 



ss. Supra-spinous fossa. 

v. Vertebral border. 

x. Axillary border. 

The coracoid process is shown at the right-hand 

extremity of the figure above, and to the 

left of the letter a. 



the vertebral border to a rounded concave, shallow, articular 
surface (g), called the glenoid cavity (into which the head of the 
upper-arm bone is received), and which is overhung in front by the 
coracoid process (c), while the acromion projects externally to it. 
The part which supports the glenoid surface is called the neck. 

The anterior and vertebral borders meet in a rounded prominence, 
while at the junction of the axillary and vertebral borders is a small 
flattened space for the insertion of a muscle called the teres major. 

The coracoid and acromion arise from distinct centres of ossifica- 
tion. The coracoid ossification contributes to form the glenoid cavity. 

The clavicle is a very small slender styliform bone, pointed at 
each end, and suspended in the flesh between the acromion process 
of the scapula and the manubrium of the sternum, but not touching 
either of those parts itself. 

§ 3. The humerus is the largest, but not the longest, bone of the 



CHAP. IV.] 



TEE SKELETON OF TEE LIMBS. 



91 



pectoral limb, and extends from the shoulder to the elbow-joint. It 
is imperfectly cylindrical, being flattened from side to side above, 
and from before backwards below. It describes a very slight 
sigmoid curve from above downwards, convex forwards above and 
concave below. 

The cylindrical part (or shaft) has its inner surface marked above 
by a wide longitudinal depression, termed the bicipital groove, 




Fig. 52.— Right Scapula. 



A. Seen from below. 

B. Seen from within. 
c. Coracoid process. 
g. Glenoid surface. 

m. Metacromion process. 



sb. Sub-scapular fossa ("with two oblique ridges) 
x. Axillary border, showing its longitudinal 

groove. 
The acromion process is seen in figure A, just 

above the letter m. 



because it lodges the tendon of a muscle called the Biceps. External 
to this is a slightly roughened and elevated tract (dr) called the 
deltoid ridge, as it serves for the insertion of the deltoid muscle. 

The lower part of the shaft has its anterior surface separated 
from the posterior surface by two lines (or ridges), one on each side, 
which become especially well marked as they approach the lower 
end of the bone. The outer (rs) of these two ridges (which is the 
stronger and more posteriorly situated of the two) is termed the 
supinator, or external condyloid ridge, while the inner one is named 
the internal condyloid, or pronator ridge. Just within it is an 
elongated opening, or foramen, called the supracondylar foramen (/<?), 
which transmits the median nerve and brachial artery. 

On the hinder surface of the shaft (which is generally convex) 
there may be detected a very slightly marked oblique groove (called 
the musculo-spiral) , passing from above downwards and outwards. 

The upper end of the humerus shows a large rounded convex 
head (h), covered, when fresh, with cartilage, and articulated to the 
glenoid surface of the scapula. This head is not placed on the 
middle of the summit of the bone, but on its hinder and inner 
aspect, so that its axis does not coincide with that of the shaft. . 

On the outer and inner sides of the head of the humerus, are two 



92 



TEE CAT. 



[CHAP. IV. 



blunt prominences. One of these (Fig. 54, t 1 ) and (Fig. 53, ]f) 
termed the greater (radial* or preaxial) tuberosity, is on the outer 
side of the summit of the bicipital groove. It reaches considerably- 
above the summit of the head of the humerus. At its hinder end is 




Fig. 53.— The Right Humerus. 



A. Front. 

B. Back. 

C. Summit. 

D. Lower end, with its hinder margin at 

the upper border of the figures. 
a. Trochlea. 
lg. Bicipital groove. 
c. Capitellum. 
ce. External condyle. 
ci. Internal condyle. 



dr. Deltoid ridge. 

fc. Supra-condyloid foramen. 

h. Head. 

o. Olecranal fossa. 

p. Surface for infra-spinatus. 

rs. Supinator ridge. 

t. Inner margin of trochlea. 

l f. Great tuberosity. 

2 /. Lesser tuberosity. 



a conspicuous depressed surface (p), for the insertion of the infra- 
spinatus muscle. The other smaller prominence is called the lesser 
(ulnar, or post-axial), tuberosity (Fig. 54, t 2 ) and (Fig. 53, 2 /), and 



* " Radial " because on the side of the 
radius, " pre-axial" because when the arm 



is vertical, it is in front of the long axis 
of the arm. 



CHAP. IV.] 



TEE SKELETON OF THE LIMBS. 



93 



is placed on the inner side of the bicipital groove. Both tuberosities 
serve for muscular attachments. 

The lower end of the humerus expands considerably, having a 
lateral prominence termed a condyle, on 
each eide, but the internal condyle (ci) pro- 
jects further inwards than does the external 
condyle (ce) outwards. 

Between these projections is placed the 
lower articular surface for the bones of the 
forearm. 

This is irregularly concave and convex. 
At its outer part is a rounded prominence 
(convex transversely as well as from before 
backwards) called the capitellum (c), which 
joins the outer bone of the fore-arm or 
radius. Internal to this is a pulley-like trans- 
versely concave surface (a), the trochlea, 
which joins the inner bone of the fore-arm 
or ulna. The groove of this " pulley " ex- 
tends completely round from the anterior to 
the posterior surface of the humerus. The 
capitellum and the trochlea run one into the 
other without any distinct demarcation. 
There is a shallow cavity in front of the 
humerus immediately above the trochlea. 
This is called the coronoid fossa, because it 
receives the coronoid process of the ulna. 
There is another much deeper fossa (o), also 
above the trochlea, but on the hinder surface 
of the humerus. This is called the olecranal 
or anconeal fossa, from the part of the ulna 
which it receives when the fore-leg is 
straightened. The inner margin of the 
distal articular surface of the humerus (t), 
descends much below its external margin. 

§ 4. The radius (which is slightly 
shorter than the humerus) is also a long 
cylindrical bone, expanded more or less at 
each end, and flattened en that side which 
is behind when the fore-leg is so placed 
that the paw rests on the ground. At its 
place of attachment above, it is the external 
bone of the fore-arm. The long middle part of the bone, or shaft, 
is a little curved, with the convexity forwards and outwards. At 
the upper part of its inner margin is a prominence called the 
tuberosity (t), into which is inserted the tendon of the biceps 
muscle. Just above this bicipital tuberosity the bone is nar- 
rowed into what is called the neck, from which rises the head (h) 
of the bone. This head is oval in shape, with a smooth margin- 




Fig. 54.— The Ixnter Aspect 

OF THE HU3IERUS. 

c. Capitellum. 

cf. Supra-condyluid foramen. 

ic. Internal condyle. 

dr. Deltoid ridge. 

h. Head. 

t. Inner margin of trochlea. 

t l . Great tuberosity. 

t 2 . Lesser tuberosity. 



94 



THE CAT. 



[CHAP. IV. 



and concave above for articulation with the capitellum of the 
humerus. 

At its lower end the radius becomes much broadened out, and its 
anterior or extensor * surface is grooved for the passage of tendons. 




-II 






wV.->: 



Fig. 55.— The Right Radius. 



A. Anterior and outer aspect. 

B. Posterior and inuer aspect. 

C. Distal articular surface for wrist. 

D. Proximal surface for humerus. 



h. Head. 

s. Styloid process. 

t. Tuberosity. 

u. Surface for ulna. 



Its outer side is prolonged into what is called the styloid 
process (s). The lower end of the bone articulates with the wrist 
by a large concave surface supporting the fore-paw, which is carried 



* Called "extensor " because the muscles which stretch the toes are attached 
to this surface. 



CHAP. IV.] 



TEE SKELETON OF THE LIMBS. 



95 



round by and with the radius in that motion of the arm and band 
which is called pronation and supination — movements which will be 
explained when the articulations and ligaments of the pectoral limb 




A 



56.— The Right Ulna. 



A. External aspect. 

B. Internal aspect. 

C. Surface of sigmoid fossa. 
c. Coronoid process. 

gs. Greater sigmoid cavity. 



Is. Lesser sigmoid cavity, 
o. Olecranon. 
r. Surface for radius. 
s. Styloid process. 



are described. The outer lower end of the radius also presents, in- 
ternally, a small articular surface for the ulna (it). 

§ 5. The ulna, or post- axial bone of the forearm, is longer than 
the humerus, and considerably longer than the radius. While the 
latter bone is broader below than above, the reverse condition obtains 
in the ulna. The shaft is flattened both in front and behind, with a 



96 THE CAT. [chap. iv. 

rather sharp inner or radial margin, to which a membrane (the 
interosseous membrane) is attached, which connects the shaft of the 
ulna with that of the radius. 

The upper end of the ulna presents a deep concavity (gs) for 
articulation with the trochlea of the humerus. This fossa is called 
from its shape, the great sigmoid cavity, and is divided unequally 
by an ill-defined vertical prominence which extends between the two 
processes which bound the fossa above and below respectively. 

The lower of these two processes is called the coronoid process (c) y 
and is received into the corresponding fossa on the front of the 
humerus. The inferior surface of its apex is rough, and serves for 
the insertion of the brachialis anticus muscle. 

The higher and much larger process is termed the olecranon (o), 
and passes into the olecranal cavity on the back of the humerus 
when the limb is stretched out. The olecranon forms the prominence 
of the elbow, and terminates in a rough process or " tuberosity," 
into which the triceps muscle is inserted. 

On the outer side of the coronoid process is a small, elongated 
concave, articular surface called the lesser sigmoid cavity (Is), destined 
for the border of the head of the radius which turns upon it. 

The lower end of the ulna presents a small, rounded, convex 
surface or head, which articulates with the adjacent surface of the 
radius. On the opposite side there is developed a large, laterally 
compressed prominence called the styloid process (s), which directly 
articulates with the wrist. 

§ 6. The carpus consists of seven small bones arranged in two 
transverse series. 

The bones of the upper or proximal row are : (1) The scapho- 
lunar bone ; (2) the cuneiforme ; (3) and the pisiforme. 

The first two together form an upper convex surface which fits 
into the distal articular cup of the fore-arm. The carpus has a 
convex dorsal surface, while its palmar surface is concave from side 
to side. 

The scapho- lunar bone (Fig. 57, si) is the largest of all. Its long 
axis is transverse. Above, it is smooth and mainly convex, and joins 
the radius. Below, it fits into a depression formed by the four distal 
carpals. From the hinder part of the outer side of the bone a 
tubercle projects outwards and backwards. To this tubercle there 
may be attached a small bone which is found within the tendon of 
a muscle here inserted. Such a bone is called a " sesamoid bone." 

The cuneiforme (c) is somewhat wedge-shaped, and articulates 
below with the innermost, or most ulnar, carpal only. 

The pisiforme (p) is a bone which projects freely backwards and 
downwards from the palmar surface, having a long, compressed and 
curved process, which ossifies separately as an epiphysis (see Fig. 60, 
pe). It is mainly supported by the cuneiform, but also articulates 
with the unciform. 

The bones of the distal row are: (1) the trapezium; (2) the 
trapezoides ; (3) the os magnum ; and (4) the unciforme. 



CHAP. IV.] 



THE SKELETON OF THE LIMBS. 



97 



The trapezium (tm) is the smallest carpal and the most radial of the 
distal series. It supports the pollex or most radial digit, for which 
it presents a saddle-shaped articular surface, namely, one both 





BONES OP RIGHT FORE-PAW. 



Fig 57.— Palmar Surface. 




Fig. 58.— Dorsal Sdrface. 


s (Above) scapho-lunar bone. 




si. Scapho-lunare. 


s (Below) sesamoid. 






td. Trapezoides. 


tm. Trapezium. 






tm. Trapezium. 


v.. Unciform bone- 






u. Unciform bone. 


c, Cuneiform bone. 






c. Cuneiform bone. 


to. Magnum. 






m. Magnum. 


mc. Metacarpals 






mc. Metacarpals. 


p. Pisiform. 






p. Pisiform. 


p l . Proximal phalanx. 






p 1 . Proximal phalanx. 


p 2 . Middle phalanx. 






p 2 . Middle phalanx. 


p 3 . Distal phalanx. 






p 3 . Distal phalanx. 


I. Pollex. 






I. Pollex. 


II. Index 






II. Index. 


III Medius. 






III. Medius. 


IV Annulus, 






IV. Annulus ; 


V. Minimus. 






V. Minimus. 


ve and convex. 


It is 


COB 


Lvex from without inwar 



concave ana convex, it is convex irom witnout inwards and 
convex from before backwards. 

The trapezoides (td) is also a small carpal. It articulates distally 
by a slight convexity, with the second metacarpal bone only. It is 
very little visible on the palmar surface. 

The os magnum (m) is considerably larger than the two preceding 
carpals. It is convex above at its so-called " head." It articulates 
below with three metacarpals, but mainly with the third, into the 
proximal concavity of which it projects. 

The unciform bone (u) is that carpal which lies on the ulnar side of 



98 



THE GAT. 



[CHAP. IV. 



the distal row. It articulates slightly with the fourth, hut mainly 
with the fifth metatarsal. Its upper surface is narrow and convex. 
Its palmar surface developes a small process which is called the 
" palmar process.' * 




m.i.e 



pt.e 



p/.e 



pa.e 



Fig. 59.— Bones of Medius Digit. 

m. Magnum. 
mc. Metacarpal. 
s. Se amoid. 
p 1 . Proximal phalanx. 
p 2 . Median phalanx. 
p 3 . Distal phalanx. 
a. Its apex embraced by claw. 
6. Sheath of bone enclosing root of claw 
externally. 



Fig. 60.— Vertical Section through Bones 
of Arm, Wrist, Pollex, and Index, to show 
Epiphyses. 

mie. The epiphysis of the metacarpal of the pollex 
wc. That of the index. 

p l e. That of proximal phalanx of pollex and index 
p 2 e. That of second phalanx of index. 
pe. That of pisiform. 
eu. That of radius. 
er. That of ulna. 
I, II, II, IV, and V. The digits. 



§ 7. The metacarpus consists of four elongated, and one short, 
matacarpal hones, each supporting a digit (toe) at its distal end. 

Each metacarpal has its proximal end, or hase, specially moulded 
so as to fit that part of the surface of the carpus which it adjoins. 
The distal end of each is in the form of a rounded head. 

The metacarpals are curved so as to he slightly concave, from 
ahove downwards, on their palmar aspect. The dorsal surface of 
each is slightly more flattened than is the opposite side. 

The first metacarpal (that of the pollex) is less than half the 
length of the shortest of the others, and differs from them by its 
mode of ossification, its epiphysis being situate only at its proximal 



chap, iv.] THE SKELETON OF THE LIMBS. 99 

end, while in each of the other metacarpals there is an epiphysis at 
the distal end only (Fig. 60). 

The proximal surface of the first metacarpal is deeply concave 
from side to side, and convex from before backwards, to suit the 
saddle-shaped surface of the trapezium which supports it. 

The four other metacarpals decrease in length outwards from the 
third, and the second is slightly shorter than the fourth, but 'longer 
than the fifth. 

The articular surfaces of the heads of the metacarpals extend 
further on the palmar than on the dorsal aspect. 

Each on its palmar aspect has a median ridge, on each side of 
which a small rounded ossicle, called a sesamoid bone (s), is attached. 

The ulnar side of the proximal end of the fifth metacarpal 
exhibits a slight prominence or tuberosity. 

The distal surface of the first metacarpal slopes obliquely down- 
wards and towards the ulnar side. 

§ 8. The toes, or digits, of the fore-paw (corresponding to our 
thumb and four fingers) have each a distinguishing name. 

Thus the first digit (thumb) is termed the pcl/ex. 

The second is the index. 

The third is the medius, or middle digit. 

The fourth is the anmdus, or ring digit. 

The fifth is the minimus, or little digit. 

Each digit consists of three rather elongated bones termed 
phalanges, except the pollex, which has but two. 

Each phalanx ossifies by an epiphysis, which is situated at its 
proximal end (Fig. 60, p l e and p 2 e). 

The two phalanges of the pollex are of nearly equal length. 

In every other digit the phalanges become successively shorter 
and smaller, the third phalanx being, however, but little smaller 
than the preceding one, while it is vertically expanded to support 
the claw. 

The phalanges of the proximal row (p 1 ) are somewhat curved 
like the metacarpals. They are smooth and transversely convex 
dorsally ; on the palmar surface they are flat or somewhat concave, 
each lateral margin being somewhat raised. At their proximal end 
each is concave (for the supporting metacarpal), but distally each 
presents two condyles divided by a shallow groove. 

The middle row of phalanges (p 2 ) are like the proximal ones, 
except that they are smaller, and that each presents at its proximal 
end a median elevation with a concavity on each side, these con- 
cavities joining the convexities of the proximal metacarpals. 

The penultimate phalanx of each digit, except the pollex, is 
hollowed out on its outer (or ulnar) side, and the ultimate phalanx 
habitually lies bent back, reposing in the cavity thus prepared 
for it. 

Each distal phalanx (Fig. 59) has its proximal end produced back- 
wards below, so that, when the bone is placed with its long axis 
horizontal, its articular surface looks upwards. Beyond this 

* H 2 



100 



THE CAT. 



CHAP. IV. 



the phalanx is very much compressed laterally, ending distally in a 
sharp, vertically-curved process (a) like the upper beak of a bird of 
prey, and greatly flattened from side to side. A thin lamella of 
bone projects forwards (b) above and on each side of the base of this 
beak, enclosing a deep groove for the reception of the claw. 

Two small round extra bones, called sesamoid bones (s), are (as 
before said) placed beneath the junction of the proximal phalanx 
and metacarpal of each of the digits. 




Fig. 61.— Connexions of Right Humerus and Scapula. 



A. Seen within. 

B. Seen from above. 
a. Acromion process. 

ah. Fibres from acromion to capsule. 

6. Tendon of biceps. 

c. Coracoid process. 

cc. Capsular ligament- 

ca. Coraco-clavicular ligament. 



ct. Clavicle. 

dh and ch. Fibres from coracoid to capsule or 

coraco-humeral ligament. 
is. Infraspinatus, cut short. 
Id. Latissimus dorsi, cut short. 
s. Sub-scapularis, cut short. 
sp. Supra-spivatus, cut short. 
t. Transverse fibres. 



§ 9. The pectoral limb, as a whole, is connected with the 
dorsal part of the axial skeleton neither by cartilage nor ligament, 
but by muscular connexion only. It is, however, connected with 
the ventral part of that skeleton, namely, with the sternum and with 
the first rib, by ligamentous union. Such a union exists between 
the sternum and the rudimentary clavicle on the one part, and 
between the clavicle and the scapula on the other part ; for the 
clavicle is connected with the coracoid process by a ligament called 
coraco-clavicular (Fig. 61, cc). 

The shoulder -joint is a remarkably free one, a]lowing the fore-leg 
to be rotated to a considerable extent in all directions. The cartila- 
ginous cup of the glenoid is deepened by a circular ligament (the 
glenoid ligament) which surrounds its margin. 

The joint is surrounded by a capsular ligament (ca), which 
extends down from the glenoid ligament round the head of the 



CHAP. IV.] 



THE SKELETON OF TEE LIMBS. 



101 



humerus, to be inserted into the neck. It is lined by synovial 
membrane. 

An accessory ligament, called the coraco- humeral (Fig. 61, dh), 
passes from the coracoid process to the capsule and great tuberosity. 





Fig. 62.— Right Elbow. 



A. Seen in front. 

B. Inner side. 

6. Tendon of biceps. 

ha. Brachialis aiUicus. 

ca. Posterior ligament. 

ef. Condyloid foramen. 

e. External lateral ligament. 



i. Internal lateral ligament. 

in. Inter-osseous ligameat. 

n. Median nerve. 

o. Orbicular ligament. 

r. Radius. 

t. Triceps, cut short. 

u Ulna. 



The lower end of the humerus so fits into the greater sigmoid 
cavity of the ulna as to permit the bending of the last-named bone 
to and fro upon the humerus. 

This joint is enclosed in a capsule furnished with a large synovial 
membrane, and surrounded by four ligaments. (1.) The internal lateral 
ligament (Fig. 62, i) radiates from the inner condyle to the coronoid 
process and inner olecranal margin. (2.) The external lateral liga- 
ment (e), which is much smaller, proceeds from the external condyle 
to what will be shortly noticed as the annular ligament of the 
radius. (3.) The anterior ligament descends from above the coronoid 
fossa, while (4) the posterior ligament (ca) proceeds from the 
margins of the olecranal fossa to the olecranon. 

The upper end of the radius articulates with both the ulna and 
humerus. Its head joins the lesser sigmoid, cavity of the ulna, 
while from the front and hinder ends of that lesser sigmoid cavity 
a strong fibrous band proceeds and unites opposite the cavity, thus 
forming a ring, the orbicular ligament (Fig. 60, A, o), which embraces 
the head of the radius. This head rotates upon the capitellum 
(round the radius's long axis) within the annular ligament. 

The radius (with the paw which it carries with it) is thus able to 



102 THE CAT. [chap, iv« 

perform the motions of pronation and supination without danger of 
dislocation. 

When the fore-leg and paw hang down, the sole of the fore- 
foot—or palmar surface — being directed forwards, the position is 
that of supination, and the hones of the fore-arm are situate side 
by side. 

. When the fore-leg and paws are placed as in the act of walking, 
the position is that of pronation, and the radius crosses over the 
ulna. 

A ligament has already been mentioned which connects the 
shafts of the radius and ulna. This is the interosseous ligament or 
membrane. It is a thin sheet of fibres which proceed obliquely 
downwards and inwards from the ulnar margin of the radius to the 
radial margin of the ulna. 

The two rows of carpal bones are connected together by dorsal, 
palmar, and lateral ligaments, so that they form an arch concave 
towards the palm. Synovial membrane is interposed between the 
proximal and the distal series of carpals. 

The anterior annular ligament is a strong fibrous band from the 
scapho-lunare and trapezium to the pisiforme, thus forming, with 
the bones, a ring through which the tendons for bending the fingers 
may pass down to the digits. 

The posterior annular ligament proceeds from the outer margin of 
the lower part of the radius to the inner part of the cuneiform and 
pisiform, forming a sheath through which the tendons for extending 
the fingers pass down to the digits. 

The proximal ends of the four ulnar metacarpals are joined to 
the carpus by dorsal, palmar, and interosseous ligaments. The first 
metacarpal is united to the trapezium by a capsular ligament. 
Synovial membranes are interposed between the successive phalanges, 
and between the phalanges and the metacarpals. The distal ends 
of the metacarpals are united to the proximal phalanges by lateral 
and palmar ligaments. 

The last phalanx of each digit is bound to the last but one by a 
very elastic ligament (Fig. 63), which passes from the dorsal surface 
of the hinder part of the distal phalanx to the distal part of the 
middle phalanx, and by its action keeps the former phalanx rolled 
back upon the latter. It is put on the stretch, and the claw is 
drawn downwards by a flexor tendon (to be described with the 
muscles), which is held in place by a ligamentous loop attached to 
the palmar surface of the proximal phalanx. 

An inter metacarpal ligament passes from the palmar aspect of the 
distal end of the metacarpal of the pollex to the distal palmar 
surface of the metacarpal of the index. 

§ 10. A general view of the pectoral appendicular skeleton, 
shows us that it forms an incomplete bony girdle, which is attached 
to the axial skeleton on its dorsal aspect by soft parts only ; but it 
is connected with the ventral parts of the appendicular skeleton 
by the clavicles and by ligaments. The elbow-joint is so bent as to 



C HAP. IV.] 



TEE SKELETON OF THE LIMBS. 



103 



open forwards, and when the body is supported as in walking, the 
fore- legs are in pronation. _ ; 

The skeleton of the fore-leg below the elbow is divisible into a 
tri- and a bi-digital series, placed side by side. 

Thus there is, first, the radius; the scapho-lunar bone; the 




63. — Digit of Fore-paw, with its Ligaments. 



Showing the elastic ligament which passes from 
above the root of the claw, downwards and 
backwards to the distal part of the second 
phalanx ; also the long flexor tendon (which 
by being pulled backwards draws down the 



claw) passing through the ligamentous loop 
attached to the under surface of the middle 
phalanx. The sesamoid bone beneath the 
distal end of the metacarpal is also shown. 



trapezium, the trapezoides, and the magnum ; the first, second, and 
third metacarpals ; and the annexed digits forming the tri-digital 
series. 

We have, secondly, the ulna ; the cuneiform ; the unciform ; the 
fourth and fifth metacarpals ; and the corresponding digits — forming 
the bi-digital series. 



THE SKELETON OF THE PELVIC LIMB. 

§ 11. The bones of the cat's pelvic limb are divisible (like those 
of its pectoral limb) into three categories : A, that of the hip ; B, 
that of the hind-leg ; and C, that of the hind-foot. 

A. The skeleton of the hip, or haunch bone, is called the os 
innominatum ; and there is one such on either side in the adult 
animal. 

B. The skeleton of the leg is sub-divisible into (a) that of the 
thigh, which consists but of one bone, called the femur ; (b) that of 
the lower part of the leg, which consists of two bones placed side by 
side. The larger of these is called the tibia ; the other, much more 
slender and placed on the outer side of the leg, is called the fibula. 
It is also called the peroneal bone of the leg, because it clasps, as it 
were, the larger bone. 

C. The skeleton of the hind-foot, like that of the fore-foot, is 



104 



THE CAT. 



[CHAP. IV. 



sub- divisible into three parts . (a) that of the ankle, the tarsus ; 
(b) that of the middle part of the foot, the metatarsus ; and (c) that 
of the toes, or digits, composed of phalanges , like those of the 
digits of the fore-paw. 

§ 12. The os innominatum is a large bone, which meets its fellow 




Fig. 64.— The Pelvis, seen in front. 

a. Acetabulum. 

Crest of ilium. 
il. Ilium. 

ip. Ilio-pectineal eminence. 
o. Obturator foramen. 



p. Pubis. 

s. Sacrum. 

sp. Symphysis pubis. 

t . Tuberosity of ischium 



of the other side in the mid- ventral line of the body, and is strongly- 
attached to the sacrum (s) above. It thus forms, with the inter- 
vention of the last-named bone, a solid bony girdle, called the 
pelvis, supporting the trunk above, and being itself imposed on 
the hind-limbs below. The head of the thigh-bone fits into a socket 
— the acetabulum (a) — on the outer side of the os innominatum. 

This bone consists of two main parts, one above and in front of, 
and the other below and behind the acetabulum. The upper portion 
forms one continuous piece of bone, but the lower part is perforated 
by a large aperture, termed the obturator foramen (o). Each os 
innominatum is made up originally of three distinct bones, which 
become united when the cat is full-grown. These three bones are 
the ilium, the ischium, and the pubis. 



CHAP. IV.] 



TEE SKELETON OF THE LIMBS. 



105 



The innominate bone thus consists of three parts : — 
(1). An elongated upper part joins the sacrum and extends down 
to the socket for the thigh. This is the ilium (il). 




Fig. 65.— Right Os Innominatum, External Aspect. 




Fig. 

a. Acetabulum. 
ar. Auricular surface. 
c. Crest of the ilium, 
i. Articular surface of pubis. 
il. Ilium. 

ip. Spiue of ischium. 
o. Obturator foramen. 



—Right Os Innominatum, Inner Aspect. 



p. Tuberosity of ischium. 

t. Pubis. 

The ilio-pectineal eminence is seen in Fig. A., 
between a and t, and in Fig. B., above t, on 
a line with the upper margin of the obturator 
foramen. 



(2). From the thigh-socket a bar of bone runs downwards, in- 
wards, and ultimately backwards. This is the pubis (Fig. 64, 
p, and Figs. 65 and 66, t). 



106 TEE CAT. [chap. iv. 

(3). Another, stouter, piece of bone curves first backwards from 
the thigh-socket, then downwards and forwards till it meets 
the pubis. This is the ischium (Fig. 46, t, and Figs. 65 and 
66, p). 

The ilium has a slightly concave outer surface, the upper border 
of which is termed the "crest" (c), and is somewhat convex and 
arched. This surface is also called " gluteal" because the gluteal 
muscles are attached to it. From the front end of the crest the 
anterior border descends sharply to the pubis, a blunt prominence 
(called the ilio-pectineal eminence) marking the point of junction. 
Another prominence (the anterior spinous process) projects from 
the anterior border of the ilium near its summit. From the hinder 
end of the crest of the ilium descends its posterior border, the 
summit of which is marked by the posterior spinous process, separated 
by a wide notch from a small marked prominence, called the spine 
of the ischium (ip). 

The inner surface of the ilium is slightly concave, forming the 
iliac fossa (il) and at its anterior and upper part is a rough irregular 
space, called the auricular surface (ar), for articulation with the 
sacrum. The ilium forms about the upper third of the socket for the 
thigh-bone. 

The pubis, or pubic bone, forms the inner part of the thigh-socket, 
joining the ilium above, and at its junction contributing to form the 
ilio-pectineal eminence. It thence descends inwards (as a band of 
bone flattened from without inwards, called the horizontal ramus) 
till it meets with its fellow of the opposite side, when it turns sharply 
backwards and downwards. The junction of the two pubes is termed 
the symphysis (sp), and the part of each pubis next the symphysis is 
sometimes called the body; thence the pubis runs outwards and 
backwards, as a flattened band, till it meets the ramus of the 
ischium. 

The ischium forms the outer and hinder part of the thigh-socket, 
and indeed of the whole os innominatum. The body of the ischium 
forms about two-fifths of the socket for the thigh, which cavity is 
situated on its anterior and outer side. The body is broad, and sends 
from its posterior upper margin a slightly marked process, called the 
spine of the ischium (ip). Behind this, and behind the socket, the bone 
contracts somewhat, and then expands again, the expansion having 
a rough, outwardly projecting prominent surface, which is called the 
tuberosity of the ischium (p) ; and it is the two tuberosities (of the 
two ossa innominata) which support the body when in the sitting 
posture (Fig. 64, t). Just below the tuberosity, the ischium sends 
forth a flat band of bone (the ramus), which, curving forwards and 
downwards, meets the bony band of the pubis spoken of above. 
Between the spine and the tuberosity of the ischium the posterior 
upper margin of the bone is slightly concave. 

The socket for the thigh-bone (which has been so often referred 
to) is called the acetabulum, or cotyloid cavity. It has a prominent 
rim, except at the inner and lower part where the rim is interrupted 



chap. iv.] THE SKELETON OF THE LIMBS. 107 

by a notch (the cotyloid notch). There is no perforation in the 
acetabulum, but its surface just within the notch is depressed, the 
depression affording attachment to the very strong ligamentum teres 
(or round ligament) which goes from it to the head of the thigh- 
bone. 

Enclosed by the ilium, ischium, and pubis, there is an oval space 
called the obturator foramen, one such being placed on each side of 
tbe pubic symphysis (o). 

The concavity in the posterior border, between the posterior 
spinous process of the ilium and the spine of the ischium, is called 
the greater ischiatic notch ; the other concavity, between the spine of 
the ischium and the tuberosity of that bone, is called the lesser 
ischiatic notch. 

The width from side to side of the pelvis is about equal to its 
depth from the brim of the pubis to midway between the tuberosities 
of the ischia. Either of these dimensions is much less than half 
the greatest extent of the ossa innominata. 

§ 13. The femt-b is a bone of about the same length as the ulna, 
and, like the humerus, is more or less cylindrical, with a rounded 
head above (to fit into the acetabulum), and with an expansion 
below with two articular surfaces. 

The shaft, which is nearly straight, is smooth in front, but has an 
oblique ridge behind, termed the linea aspera, which is most marked 
about half-way up the bone (la). 

At the upper end of the shaft are two conspicuous projections. 
The external one of these (projecting from the outer margin of the 
bone, which it continues upwards), is called the great, or peroneal 
trochanter (gt). The internal projection, which is much smaller, 
more conical, and rounded, stands out from the inner and hinder 
side of the bone, and is called the lesser, or tibial trochanter {It). 

Between the two trochanters, on the hinder side of the femur, a 
bony prominence extends, which is termed the posterior inter- 
trochanteric ridge (r) ; and a very slightly marked line, the anterior 
inter -trochanteric ridge, also connects the two trochanters on the 
front surface of the femur. 

On the inner and hinder side of the great trochanter is a pit, 
termed the trochanteric fossa (f). 

From between the inter-trochanteric ridges a narrower portion of 
bone, compressed antero-posteriorly, projects inwards, forming a 
slightly obtuse angle with the shaft. This is called the neck of the 
femur (n). It ends in a rounded head (forming a large part of a 
sphere) which (h) fits into the acetabulum. 

On the hinder part of the inner side of the head of the femur 
there is a very distinctly marked depression, or pit, which serves for 
the attachment of the ligamentum teres (p). 

On the outer side of the hinder part of the femur, a little below 
the great trochanter, is a more or less marked vertical ridge, which 
serves for the insertion of the gluteus maximus muscle. 

At the lower end of the femur are two rounded prominences, 



108 



THE CAT. 



[CHAP. IV. 



elongated from before backwards, and of nearly equal size, named 
condyles, separated behind by a median depression (ap). 

The external condyle (ec) has on its outer surface a depression for 
the tendon of the popliteus muscle. Immediately above this is the 
slight prominence of the external tuberosity, immediately above 





Fig. 67.— The Right Femi-r. 
A. Anterior aspect. B. Posterior aspect. 



which is a small, but deeply marked pit for the tendon of the gastro- 
cnemius muscle, and the sesamoid to which that tendon is attached. 

The internal condyle is slightly longer, and descends a little lower 
down than the external one. On its inner side is a projection called 
the internal tuberosity {it). 

The articular surfaces of the condyles meet in front, and form an 
elongated, transversely concave, ascending articular surface (ap) for 



CHAP. IV.] 



THE SKELETON OF THE LIMBS. 



109 



the knee-pan. Posteriorly they diverge, leaving between them a 
space called the inter -condyloid fossa {if). The femur does not 
articulate with the fibula. 




EXPLANATION OF LETTERS IN FIGS. 67 AND 



C. External view. 

D. Internal view. 

E. Proximal end. 

F. Distal end. 

ap. Surface for patella. 
ec. External condyle. 
et. External tuberosity. 
/. Trochanteric fossa. 
gt. Great trochanter. 
h. Head. 

ic. Internal condyle. 
if. Inter-condyloid fossa. 
it. Internal tuberosity. 



la, Linea aspera. 

It. Lesser trochanter. 

n. Neck. 

p. Pit tor ligamentum teres. 

r. Posterior inter-trochanteric ridge. 

In Fig. C, a depression may be observed at the 
lower end of the shaft posteriorly, just above 
the external condyle. It is for the sesa- 
moid to which the' gastrocnemius muscle is 
attached. The depression in the hinder 
part of the external condyle itself, is for 
the tendon of the popliteus muscle. 



§ 14. The knee-pan, or patella, is a small bone of an elongated 
oval shape, which is convex in both directions externally, while 
internally it is convex transversely, but concave from above down- 



110 



THE OAT. 



[CHAP. IV. 



wards, and so fits into the median articular surface at the lower end 
of the front surface of the femur. 




em 



Fig. 69.— The Right Tibia and Fibula, seen 

IN FRONT. 



A. Tibia. 



B. Fibula. 



Fig. 70.— The Right Tibia and Fibula, 

BEHIND. 



A. The tibia. 



B. The fibula. 



It is attached ahove hy its hroad upper margin to the tendon of 
the front muscle of the thigh. Below, a ligament goes from its 
pointed lower end to the upper part of the shin-bone. 

§ 15. The tibia, or shin-bone, is the absolutely longest bone in 
the cat's skeleton. It transmits the weight of the hinder part of 
the body from the thigh to the foot. 

Its upper end is very wide, and presents two articular surfaces 
(condyles) — which are each convex from before backwards, and 
slightly concave from side to side (ec and ic), and which receive the 
two condyles of the femur. Between these articular surfaces there 
is a depression, or pit, giving insertion to one end of one of the 
crucial ligaments which connect the femur with the tibia. 



CHAP. IV.] 



THE SKELETON OF THE LIMBS. 



Ill 



On the two sides of the proximal end of the tibia are two projec- 
tions, respectively supporting the condyles, and called the external 



c— 




A. Inner surface. 



Fig. 71.— The Right Tibia. 
B. Its proximal end. 



C. Its distal end. 



EXPLANATION OF LETTERS IN FIGS. 69, 70, AND 71. 



c. Crest. 

ec. External condyle. 

em (Fig. 69, B). Is the external malleolus, the 
hinder surface of which is grooved for the 
tendon of the peroneus brevis muscle. 

em (Fig. 70, B). Is that surface of the external 
malleolus, which articulates with the fibula. 

et. External tuberosity. 

•t. Flattened surface for fibula below. 

fs. Surface for fibula above. 



ic. Internal condyle. 

im. Internal malleolus. 

is. Inner surface for astragalus. 

it. Internal tuberosity. 

os. Outer surface for astragalus. 

p. Descending process. 

t. Tuberosity. 

Between im and p (Fig. 70, A) is the groove for 

the tendon of the flexor longus hallucis 

muscle. 



and internal tuberosities (et and it). The external one presents 
beneath a very small elongated surface for articulation with the 
upper part of the fibula {fs). 



112 THE CAT. [chap. iv. 

The shaft of the tibia is generally triangular in section, being 
produced into a sharp crest (c) in front, on the internal side of which 
crest the bone is more or less flattened, while it is strongly concave 
on its outer side. At the upper end of the front of the shaft is a 
prominence called the median tuberosity (t), or tubercle, which 
exhibits a flattened surface for the attachment of the patella. 

The lower end of the bone is smaller than the upper. Its lower 
border has a single wide, vertical groove behind for the tendon of 
the flexor longus hallucis muscle. Its outer surface is flattened [fi) 
for the reception of the fibula. Its inner margin is produced down- 
wards into a strongly marked triangular process, called the internal 
malleolus (im). This forms the bony projection on the inside of the 
ankle, and articulates with the inner side of the tarsus. The 
posterior part of the non- articular, -or free, surface of the internal 
malleolus, shows two small strongly marked vertical grooves, the 
anterior of which transmits the tendon of the tibialis posticus muscle, 
while the more posterior and outer is traversed by that of the flexor 
longus digitorum muscle. 

The lower end of the tibia presents an irregular and undulating 
articular surface, corresponding with the surface of the tarsus, which 
it joins. This surface presents a median ridge running obliquely 
backwards and inwards from its front margin, and fitting into the 
groove on the upper surface of the astragalus. On the outer side of 
the ridge is a rather wide articular surface (os), which slopes upwards 
and outwards ; on its inner side is a more concave, but less inclined 
surface (is), which becomes continuous with the articular surface borne 
by the internal malleolus. The hinder margin of the articular sur- 
face of the tibia (when the bone is vertical) descends slightly below 
its front border, which nevertheless exhibits a descending process (p) 
which corresponds with the front end of the median ridge just 
described. 

§ 16. The fibula is the slenderest bone, in proportion to its 
length, in the body, and extends on the outer side of the leg from 
close to the knee down to the ankle. 

Its upper extremity is slightly enlarged into what is called the 
head, which articulates with the outer side of the head of the tibia, 
and gives insertion to the external lateral ligament. It does not 
mount upwards so high as does the tibia, and its outer surface is 
concave. 

The shaft of the bone is irregularly triangular in section. Its 
lower end is expanded into what is called the external malleolus, 
which forms the bony projection on the outer side of the ankle, and 
articulates with the outer side of the tarsus. 

This malleolus does not project downwards so far as does the 
internal malleolus. On its inner side it articulates anteriorly with 
the outer side of the lower end of the tibia (as already mentioned) 
below and behind this it articulates with the outer side of the 
astragalus. The external malleolus is deeply grooved behind for 
the passage of the tendon of the peroneus brevis muscle, while that 



chap, iv.] THE SKELETON OF* THE LIMBS. 113 

of the peroneus longus muscle passes in front of the external 
malleolus. 

Thus, altogether we have at the lower end of the cat's leg, a 
median horizontal surface for the tarsus, with two other articular 
surfaces, at right angles with the horizontal one, and formed by the 
surfaces of the malleoli. 

§ 17. The tarsus consists of seven bones (none of which can be 
called "long bones"), namely the astragalus, calcaneum, cuboides, 
naviculare, and three cuneiform bones. All these are so firmly 
connected by ligamentous fibres which envelope them, that very 
little mobility is possible, though there may be a very slight rotation 
of the distal tarsal bones upon the proximal ones, that is, upon the 
astragalus and calcaneum. 

The movement of the foot on the leg, however, takes place entirely 
by the hinge-like joint by which the tarsus articulates with the bones 
of the leg. 

The astragalus receives the weight of the trunk from the tibia, 
and is a short irregularly shaped bone (Fig. 73, as), with a " body, 
neck, and head." 

In its natural position in walking, when the foot rests on the 
ground only by its toes (the heel being raised high up) the upper 
surface of the body of the astragalus (by which it articulates with 
the under surface of the shaft of the tibia) looks forwards as well as 
upwards. Two other articular surfaces, almost at right angles with 
the former, join the two malleoli respectively, that for the internal 
malleolus being much the larger. The posterior surface of the body 
is grooved for the tendon of the flexor longus hallucis muscle. The 
anterior part of the bone is prolonged forwards as its neck, ending 
in a rounded, convex, articular surface (the head), which fits into 
the hinder surface of the naviculare (n). The anterior part of the 
dorsum of the bone presents a concavity, which gives origin to the 
extensor brevis digitorum muscle, and also affords attachment to a 
tendinous loop through which pass the tendons of the extensor 
longus digitorum muscle. 

The calcaneum (or os calcis) is the bone of the heel (oc), and is by 
far the largest bone of the tarsus. It is rather more than twice as 
long as broad, and is somewhat expanded at its hinder end (called 
its tuberosity), which, is vertically grooved to allow the tendon of 
the Plantaris muscle to play over it (Fig. 72, oc s ). The calcaneum 
articulates with the astragalus above and with the cuboid in front. 
It developes a process on its inner side (x) to support part of the 
last-named bone, and another smaller process (oc 3 ) on its outer side 
just before joining the cuboids. 

The naviculare (or scaphoid of the foot) is, on its dorsal surface, 
wider than long (Fig. 73, h). Behind, it is deeply concave for the 
reception of the head of the astragalus. In front it presents three 
surfaces for articulation with the three cuneiform bones. That for 
the middle one is convex. 

Its inner margin sends backwards a long process, called its 



114 



THE CAT. 



[chap. rv. 



tuberosity, which extends (n* and u) beneath (i. e., on the plantar 
side of) the head of the astragalus and supports it. 





BONES OF RIGHT HIND-PAW. 



Fig. 72.— Plantar Surface. 

a. Hood to enclose root of claw. 

as. Astragalus. 

6. Process to sustain claw. 

cb and ch. Cuboides. 

oc. Os calcis. 

oc 1 . Inner process. 

oc 2 . Outer process of os calcis. 

oc 3 . Groove for tendon of Plantaris. 

mc. Meso-cuneiform. 

mt. Metatarsals. 

n l . Tuberosity of Naviculare, as seen on the 

plantar surface. 
nc. Ento-cuneiforme. 
p l . Proximal phalanx. 



Fig. 73.— Dorsal Surface. 

p 2 . Middle phalanx. 

p 3 . Distal phalanx. 

t. Ecto-cuneiform. 

tcp. Its hooked plantar process. 

u. Tuberosity of naviculare, as seen on dorsal 

surface. 
X (Fig. 72) inner process of os calcis. 
x (Fig. 73) the tuberosity of fifth metatarsal. 

I. Hallux, only represented by its metatarsal. 

II. Index. 

III. Medius. 

IV. Annulus. 

V. Minimus. 



CHAP, iv.l THE SKELETON OF THE LIMBS. 115 

Of the three cuneiform hones, the outermost one — ecto-cunei- 
form, is the largest, and the mem-cuneiform is the smallest, and is 
not to he seen on the plantar surface of the foot. The ento-cuneu 
form is longest from behind forwards. It presents behind a concave 
articular surface for the naviculare. Above it has posteriorly a 
concave articular surface for the meso-cuneiform, and anteriorly a 
much smaller one for the second metatarsal. In front it has a flat 
surface (elongated from the dorsum to the plantar aspect) for the 
rudimentary first metatarsal. The meso-cuneiform is a wedge-shaped 
hone with its broad end on the dorsum of the foot. Behind it presents 
a concave articular surface for the naviculare, and it has another 
concave articular surface in front for the second metatarsal. The 
ecto-cuneiform has both in front and behind a large articular surface, 
broad dorsally, and narrow towards the plantar surface. The former 
articular surface is for the naviculare, the latter for the third meta- 
tarsal. It has also on its inner side a small articular surface for the 
meso-cuneiform, and on its outer side a much larger one for the 
cuboides. The hinder, or proximal part of its plantar surface sends 
downwards and distally a strong hook-shaped process (tqpi), between 
which and the plantar surface of the bone, the tendon of the 
peroneus longus muscle passes. 

The cuboides, placed on the outer side of the tarsus (cb), articu- 
lates with the os calcis behind, and with both the fourth and fifth 
metatarsals in front. Its inferior surface is traversed by a deep 
groove (for the tendon of the peroneus longus muscle), behind which 
is a prominence for the attachment of a ligament. 

§ 18. The metatarsus consists of four elongated bones (the 
shortest of them being more than half the length of the radius), and 
one excessively short and rudimentary one (1 ) which is placed on 
the inner or tibial side of the other four. 

The four long metatarsals are much more elongated than are the 
corresponding: metacarpals, and the second of them (that of the third 
digit or medius of the foot) is also much stouter than is any one of 
the latter. 

The innermost metatarsal is the only bone which represents the 
first or innermost digit. It is called the hallux, and corresponds with 
the pollex of the fore -paw. This first metatarsal is a minute conical 
bone, smaller even than the meso-cuneiform. It has an oblique 
articular surface at its proximal end, which articulates with the 
ento-cuneiforme, while on its inner side is another articular surface 
for the second metatarsal. 

The four outer metatarsals have their bases or tarsal ends en- 
larged, and each provided with a proximal articular surface (dif- 
ferent in shape in each metatarsal) for the tarsus, situated in a plane 
nearly at right angles with the long axis of each respective meta- 
tarsal. The proximal articular surface of the second metatarsal is 
small and triangular ; that of the third is very large and crescentic ; 
that of the fourth is moderate in size and quadrangular ; that of the 

i 2 



116 THE CAT. [chap. iv. 

fifth is very small and oval, and with a long process or tuberosity 
extending backwards on its outer side (x). 

The shafts of the four outer metatarsals are flattened dorsally and 
on their plantar surface, and where they are in contact towards their 
proximal ends. That of the medius is the longest and the stoutest ; 
that of the fifth digit is the most slender, and that of the index of 
the foot, the shortest. Each of these four outer metatarsals develops 
a rounded head at its distal end, which articulates with the concavity 
on the hinder end of the proximal phalanx of the corresponding 
digit. As in the corresponding part of the metacarpals, there is a 
prominence developed at the middle of the ventral surface of each 
such distal, articular head — a sesamoid bone playing in the concavity 
which exists on each side of such prominence. 

§ 19. The phalanges are three in number in each digit, except 
the first or hallux, which is devoid of any. 

In form and arrangement the phalanges of the hind-foot closely 
resemble those of the fore-foot, except that the proximal ones of the 
outermost (peroneal) digits are longer and stouter. 

§ 20. The ARTICULATIONS AND LIGAMENTS OF THE PELVIC GIRDLE 

are as follows : — 

In the first place, each ilium is united to the adjacent auricular 
surface of the sacrum by cartilage which there coats both bones, and 
forms what is called the sacro-iliac synchondrosis. Ligaments called 
the dorsal and ventral sacro-iliac ligaments strengthen this articula- 
tion on each side. The pubes are joined together at the symphysis by 
the help of a fibro-cartilage, and by superior and inferior ligaments. 

The obturator foramen is closed by means of the obturator mem- 
brane (or ligament), which is attached to its margin or inner edge. 

The socket offered by the bony pelvis to the head of the femur is 
deep, but it is made still deeper by the cotyloid ligament, which 
surrounds its margin and bridges over the notch at its lower part, 
forming there what is called the transverse ligament. 

The movements of the thigh, therefore, though still extensive, are 
more restrained than those of the fore-limb at the shoulder-joint. 
The head of the femur is held in its socket in part by a very strong 
ligament called the ligamentum teres, which is at one extremity con- 
tinuous with the transverse ligament, while at its other end it is 
inserted into the pit on the head of the femur. 

The joint is surrounded by a capsular ligament, strongest in front, 
attached above to the margin of the acetabulum and the transverse 
ligament, and below to the intertrochanteric line in front, but at a 
higher level behind. It is lined by synovial membrane. 

The articulations and ligaments of the hind- leg are ex- 
ceedingly complex. 

The internal lateral ligament (Fig. 74, i) extends from the internal 
tuberosity of the femur to the inner tuberosity of the tibia. The 
tendon of the semi- membranous muscle (sm) passes between it and 
the bone. 



CHAP. IV.] 



THE SKELETON OF THE LIMBS. 



Ill 



The external lateral ligament, very strong and distinct (e) passes 
as a flattened cord from the external tuberosity of the femur to the 
head of the fibula. 

The posterior ligament ( p) is a narrow band extending obliquely 
upwards from the outer part of the summit of the tibia to the 
internal condyle of the femur. 




A B 

Fig. 74.— Ligaments, with some Muscular Insertions; of*the Knee-joint. 



A. Seen posteriorly. 


1. Inter-osseous ligament. 


B. Seen externally. 


p. Posterior ligament. 


ae. Anterior crucial ligament. 


p>a. Patella. 


b. Biceps muscle. 


pc. Posterior crucial ligament. 


c. Upper attachment of capsular ligament. 


s. Inter-articular cartilage. 


e. External lateral ligament. 


sn. Semi-membranosus. 


ed. Extensor lougus digilorum. 


tf. Tibio-fibular ligament. 


g. Gastrocnemius. 


tp. Ligament pf the patella towards its inser- 


i. Internal lateral ligament. 


tion. 



The ligamenlum patellae (tp\ is a strong fibrous band proceeding 
upwards from the anterior tubercle of the tibia to the lower end of 
the patella. The patella (pa) is supported above by the tendon of 
the rectus muscle which is inserted into it, and indeed, the liga- 
mentum patella? may be viewed as the inferior termination of that 
tendon, and the patella itself as a large sesamoid bone. This 
ligament aids powerfully in preventing the flexion of the knee 
forwards, there being in the leg no process like the olecranon of the 
ulna to prohibit (by the mere shape of the leg-bones themselves) a 
bending of the joint in the wrong direction. 

Two other fibrous bands, termed the crucial ligaments, are placed 
in the centre of the knee-joint, and slightly cross each other, 
whence their name. The anterior (or external) one (ae) goes from 



118 



THE CAT. 



[CHAP. IT 




the pit between the condyles of the tibia to the inner and posterior 
part of the external condyle. The posterior (or internal) one (pc) 
goes from a more posteriorly situated part of the same pit to the 
front part of the concavity between the condyles or the outer side of 
the inner condyle. Two fibro-cartilaginous crescentic structures (s), 

the semi-lunar cartilages, are inter- 
posed between the femur and the 
tibia, reposing on the outer and inner 
margins of the upper surface of the 
latter. 

A capsular ligament surrounds the 
knee-joint incompletely, being deficient 
beneath the tendons of the muscles, 
and in the regions occupied by the 
other ligaments. 

A very large membrane of the kind 
called synovial (the largest such mem- 
brane in the cat's body) lines the knee- 
joint, extending up above (and within) 
the patella, and investing the crucial 
ligaments in front, and both surfacej of 
the semi-lunar cartilages. 

The ripper ends of the tibia and 
fibula are connected by two small flat 
and oval surfaces, bound together by a 
tibio-fibular ligament (tf) passing from 
the head of the fibula to the external 
tuberosity of the tibia. 

An inter-osseous membrane, or liga- 
ment (I) , passes from the external 
ridge of the tibia to the adjacent 
surface of the fibula. It does not 
ascend quite to the summit of the 
interval between the leg-bones. 

The ARTICULATIONS AND LIGAMENTS OF THE FOOT are SO closely 

connected with those of the inferior ends of the leg -bones that these 
latter may best be described with the former. 

The ankle-joint is strengthened by anterior and posterior liga- 
mentous bands. 

The internal lateral ligament of the ankle-joint passes down 
(broadening as it descends) from the end of the internal malleolus 
somewhat to the astragalus and oscalcis, but especially to the tube- 
rosity of the naviculare. 

The external lateral ligament also radiates as it descends from the 
lower end of the fibula to the os calcis. The internal malleolus 
descends somewhat below the external one, and the tibia descends a 
little more behind the astragalus than it does in front of it. 

A certain amount of motion is possible between the distal tarsals, 
and the astragalus and os calcis — a movement facilitated by the 
presence of synovial membrane. 



:. 75. — Vertical Section through 
Knee-joint. 

a. Anterior crucial ligament (cut 

short). 

b. Bursa. 

c. c, c. Capsular ligament. 
/. (Above) femur. 

/. (In the joint) adipose tissue. 
Ip. Ligament of the patella. 
p. Posterior crucial ligament. 
pa. Patella. 
s. Inter-articular cartilages 



chap, iv.] TEE SKELETON OF THE LIMBS. 119 

A strong interosseous ligament proceeds vertically downwards 
from the groove on the under surface of the astragalus to the 
depression on the dorsum of the os calcis. 

A plantar ligament, called the calcaneo-sesphoid, connects the 
plantar surface of the naviculare with the os calcis, and so helps to 
sustain the anterior part of the astragalus. Another ligament, 
called the long plantar, joins the under surface of the os calcis with 
the cuboid and tuberosity of the fifth metatarsal. A variety of 
other ligaments connect one with another the various more distally 
situated tarsals. 

The metatarsal bones are connected with the distal tarsals by 
dorsal and plantar ligaments. 

A transverse metatarsal ligament connects the distal ends of the 
metatarsals as in the fore-foot. 

Ligaments connect the metatarsals with the phalanges, and the 
phalanges with one another in the hind-foot in the same way as the 
metacarpals and phalanges are severally connected in the fore-paw. 

§ 21. A general view of the pelvic appendicular skeleton of 
the cat shows us that it forms a complete bony girdle, being im- 
mediately attached (at the sacrum) to the axial skeleton dorsally. 
Yentrally its two sides meet together uninterruptedly at the pubic 
symphysis, and there are two ventral bars, the pubis and ischium, 
instead of only one, and that incomplete, as in the pectoral arch. 
The knee-joint is so bent as to open backwards, and thus the digits 
of the hind- foot are applied to the ground without the need of any 
pronation of the limb-bones. 

The skeleton of the leg and foot is divisible into a tri- and 
bi-digital series placed side by side. 

Thus there is first the tibia ; the astragalus and naviculare ; the 
three cuneiform bones ; the first, second, and third metatarsals, and 
the index and middle digits — forming the tri-digital series. 

We have secondly, the fibula ; the calcaneum and cuboid ; the 
fourth and fifth metatarsals ; and the annexed digits — forming the 
bi-digital series. 

§ 22. Thus it is evident that there is a great correspondence, 
and at the same time a certain difference, between the skeletons 
of the pectoral and pelvic limbs. 

The most notable correspondences are the expansion of the dorsal 
bone of each limb-girdle ; the existence of a single bone with two 
eminences (tuberosities or trochanters) in the proximal limb- segment, 
and of two bones in the distal limb-segment ; the agreement in 
number of the carpal and tarsal bones, of the metacarpals and meta- 
tarsals, of the epiphysial ossifications of these, and the corre- 
spondence in number of the phalanges, except those of the poller 
and hallux. 

Thus these limb- skeletons are evidently modifications of one type. 

The most notable differences are (1) as regards the dorsal attach- 
ments of the limb-girdles, and (2) the degree of complexity of their 
ventral parts ; (3) the fact that the outer or radial tuberosity in the 



120 THE CAT. [chap, iy. 

humerus is the larger, while in the femur it is the inner or peroneal 
one ; (4) that the ulna is the larger bone in the arm, while the 
fibula is much the smaller in the leg ; (5) that the ulna is the main 
element of the elbow-joint, while the fibula is excluded from the 
knee-joint ; (6) that the ulna sends up a very large process (the 
olecranon) at its proximal end, while the fibula sends up no process 
at all ; (7) that in the knee-joint there is a patella, while there is 
no such structure in the elbow-joint ; (8) that the tarsus is grasped 
between the malleoli, while so complete a grasp is not given by the arm- 
bonestothe carpus; (9) that there is no bone so large, either absolutely 
or relatively, in the carpus, as is the os calcis in the tarsus ; (10) 
that the pollex rests on a saddle-shaped surface, and is slightly 
separable from the other digits, while the rudimentary hallux rests 
on a nearly flat surface, and has almost no mobility ; (11) that the 
metatarsals are long as compared with the metacarpals ; (12) that 
the tarsus is much longer than is the carpus ; (13) that the hallux 
is much more rudimentary than is the pollex. 

Though many of these differences are incapable of reduction, yet 
others disappear, and serial homologies become more manifest, 
if the limbs be placed in that position which is primitive in develop- 
ment, i.e., if both the knee and elbow be turned outwards. Then 
the pollex and hallux, and the ulna and tibia, stand in corre- 
sponding positions in relation to the long axis of the body. 

As to which parts of the os innominatum answer to the several 
parts of the scapula, different views may be maintained ; but if the 
lower end of the scapula be rotated outwards, then its subscapular 
fossa will be seen to answer to the gluteal surface of the ilium, the 
acromion to the ischium and the coracoid to the pubis, the infra- 
spinatus and iliac fossae corresponding. 

Undoubtedly the femur, is the serial homologue of the humerus, 
and its great trochanter, of the lesser tuberosity ; the radius, of the 
tibia; the ulna, of the fibula; the astragalus, of the scapho-lunar bone; 
the en to-cuneiform, of the trapezium; the cuboicles, of the unciform, 
and the hallux and other pedal digits are the homologues of the pollex, 
and the other digits of the hand. 

§ 23. Such being the main facts as to the structure of the internal 
skeleton, before concluding the subject a few words are needed with 
respect to the joints. For, as has been already pointed out, the 
bones serve as points of attachment for the moving organs or muscles 
which make use of them as so many levers or fulcra, as the case 
may be. 

In order that this motion of the bones may take place easily, the 
interposition is required of certain accessory structures between bony 
surfaces which move one upon the other. Some bones, however, 
are united by surfaces which join without any such intervention — 
no motion taking place at the line of junction of such bones. 

Joints may be of three sorts : I. immovable ; II. mixed ; or 
III. movable. 

The immovable joints (synarthroses) may be (1) such as those 



chap, iv.] THE SKELETON OF THE LIMBS. 121 

which take place "between certain bones of the skull where, as we 
have seen, an interdigitation of the processes of their irregularly- 
shaped margins takes place, forming what is called a dentated or 
serrated suture (as between the parietals or frontals) ; or (2) such as 
those between the upper jaw-bones, where there is no inter- 
digitation, and where the adjoined even edges form what is termed 
an harmonia or false suture ; or (3) such as that formed by the 
temporal bone with the parietal, where the adjacent margins are 
"bevelled off and one overlaps the other, forming what is called a 
squamous suture ; or (4) such as that between the ethmoid and the 
vomer, where a ridge of one bone is received into a groove in 
another which is called schindylesis ; or finally (5) wfyere one hard 
part is received into the cavity of a bone, as the teeth fit into the 
jaws, a mode of union named gomphosis. 

In all the immovable joints- no cartilage is interposed, there being 
only periosteum, such as coats all bones. 

The great majority of the bones, however, are intended to move 
one upon another, and are on that account joined together by means 
of some other and thicker substance than the periosteum. 

The mixed or imperfect joints (amphiarthroses) bave, however, 
very little mobility, and their adjacent parts do not present smooth 
surfaces, but are connected by fibrous -tissue or continuous cartilage, 
or both. 

Examples of such joints are to be found in the junction of the 
haunch -bones with the spine, or in that formed by the bodies of the 
vertebrae one with another. These latter are connected, as we 
have seen, * by discs, each consisting, towards its circumference, of 
fibres running obliquely upwards and downwards, and in its middle, 
of a pulpy substance containing many cartilage corpuscles. These 
pads, while allowing very little movement between any two adjacent 
bones, give a considerable amount of mobility to the whole series. 
They also serve to prevent shock. 

In all movable or complete joints {diarthroses) the opposed ends 
of the bones are covered each with its own distinct, separate, and 
very smooth cartilage, and thus the bones can glide freely on each 
other. 

In addition to this, however, each complete joint is provided (as 
has been already indicated in various instances) with a kind of bag 
containing a viscid fluid. This bag, at first complete, comes in 
adult life to be attached to each of the cartilaginous surfaces, 
near its border, and to disappear altogether over the central part of 
each such cartilage. By the fluid thus interposed between the 
cartilages all friction is avoided, and a perfectly smooth, easy, and 
even motion is provided for. 

The fluid is termed synovia, and is an albuminous liquid commonly 
called "joint-oil," yet it is not really of an oily nature, although it 
contains some fatty matter. 

* See ante, p. 52. 



122 THE CAT. [chap. iv. 

The bag, formed of areolar tissue lined with scaly epithelium, is 
called the synovial capsule or membrane. It is more or less 
connected with the fibrous bands, or ligaments, which bind the 
bones together in the neighbourhood of the joints and generally 
help to restrain movement to certain directions. 

In certain joints, as in that of the cat's knee, additional structures 
are interposed, called inter-articular cartilages. These are 
formed of fibro-cartilage, and, though placed between the bones, are 
not within the cavity of the synovial sac, but attached to its outer 
surface, which is so folded or doubled as to embrace them. 

Movable joints are of different kinds, with corresponding diversities 
of form. Thus they may be such that the bones are capable of 
nothing more than a slight gliding movement one on the other, the 
apposed articular surfaces being nearly flat and even. Such joints 
are termed planiform, or arthrodia, and as examples may be 
selected the bones of the carpus and tarsus. 

A second kind of joint is that called ball-and-socket, or enar- 
throdia, where one rounded portion of bone is received into a 
corresponding cup or socket. When the cup is very deep, the cavity 
is said to be cotyloid — as in the hip -joint ; when it is shallow, it is 
said to be glenoid, as in the shoulder. The .shallower is the cavity, 
the freer and wider is the power of motion. If the terminal con- 
vexity is elongated it is termed a condyle — as is the articular head 
of the lower jaw, 

A third and a more complex kind of articulation is called a 
hinge or ginglyform joint, and is also called pulley-like or 
trochlear. In such joints the surface of one bone is more or less 
cylindrical, and fits into a corresponding socket. The former gene- 
rally exhibits a median groove with a projection on each side of it, 
while the other bone has a corresponding median prominence bordered 
by two concavities ; but various arrangements of opposing curves may 
exist, tending to limit motion more or less completely to one plane. The 
best example of such a joint is that of the elbow, a more imperfect 
one is that of the knee. This kind of joint may be so complicated 
as to form what is called a doable hinge-joint (as between the meta- 
carpal of the pollex and the trapezium) . In that articulation each 
bone is concave in one direction, and convex in the direction at right 
angles with the former, that is to «ay, each bone presents a saddle- 
shaped surface, and the two articulate together, as a rider is placed 
with respect to the saddle he bestrides. 

There is another kind of joint, rarely found, and termed a ring 
and collar-joint, or lateral ginglymus. It is when the head of a 
bone is received into a strong ring or collar, formed of ligament, 
which allows the bone to rotate round its own axis. Such a joint 
exists between the upper (proximal) parts of the two bones of the 
fore -arm. 

The last kind of joint to be noticed is that called a pivot- joint, 
an example of which is furnished by the two uppermost bones of the 
neck. Here one bone serves as an axis or pivot on which the other 



chap, iv.] THE SKELETON OF THE LIMBS 123 

can rotate. It resembles in principle the joint last noticed, but here 
the part bearing the ring (which ring is formed partly of bone, partly 
of ligament) itself turns on the bone, which traverses it instead of the 
reverse. 

Certain ligaments are called elastic ligaments, because they contain 
elastic tissue, and so serve to sustain weight, and overcome persistent 
resistance, without the necessity of expending any muscular power. 
Such are the ligaments between the neural arches of the vertebrae 
and their continuation onwards to the occiput (to support the head), 
as the Ugamentum nuchas. 



CHAPTER V. 

THE CAT'S MUSCLES. 

§ 1. The cat performs conspicuous general bodily movements — 
locomotive actions, such as walking, running, and jumping — and also 
a number of movements of various portions of the body. Some of its 
movements resemble those which are executed by ourselves at will, 
and therefore called " voluntary motions ;" others resemble those 
which we know to be in ourselves automatic, or involuntary. 

Amongst the voluntary movements are the various movements of 
the several members, such as the tail, the tongue, &c, together with 
those by the aid of which the animal may change its facial expres- 
sion, or may give audible expression to its various feelings. 

Amongst its involuntary or automatic movements are those which we 
shall find take place in the heart, intestines, and in other viscera. 

All these motions, of whatsoever sort, are performed by muscles 
of different kinds, shapes, and sizes. 

It is of muscles that the bulk of the cat's body — that is to say, all 
its " flesh " — is formed. The muscular system, therefore (by investing 
the endo-skeleton as it does), largely determines the shape of the 
trunk and limbs, though its essential function is the production of 
motion. 

The study of the muscles is called myology. 

The muscular system of the cat consists of masses of very different 
sizes and shapes, arranged in most various aggregations of muscles, 
such aggregations being separated from each other by delicate 
sheets of connective tissue called fascia? or aponeuroses. Yet more 
delicate fibrous membranes invest every single muscle, and penetrate 
between its component portions, conveying nerves and blood-vessels 
to them. 

Other skeletal structures with which the muscles are directly 
connected, are those dense bands of connective tissue already 
referred to as " tendons." 

§ 2. Muscular substance constitutes a peculiar kind of tissue. It 
is a motor tissue because it has the power of producing motion by 
" contraction," that is, by an alteration in its shape which affects 
the parts of the body to which it is attached. It has also a special 
chemical composition. It is made up for nearly three-fourths of 



CHAP. V.] 



THE CATS MUSCLES. 



125 



its substance of water, while about fifteen per cent, of the remaining 
fourth is found, after death, to consist of an albuminoid substance 
called syntonin, or muscle fibrin* which is soluble in dilute hydro- 
chloric acid. It seems, however, that this post-mortem condition 
differs from what is found in life, when the muscle-fibrin is fluid, 
and has been termed myosin. Muscle-fibrin contains some fifteen 
per cent, of nitrogen. Other nitrogenous substances termed hreatin 
and kreatinine, are present in very small quantities, as also some 
non-nitrogenous ones, such as grape-sugar, lactic, butyric, acetic, 
formic, and uric acids, with some other substances. 

Muscular tissue is of two kinds, called respectively striped and 
unstriped. The unstriped tissue takes part in the formation of the 
alimentary canal and other viscera, such as the bladder. It also 
exists in the walls of the blood-vessels, and generally in parts the 
actions of which, in man, are not under the control of the will 
Striped muscular tissue, on the contrary, makes up the substance of 
all those muscles which answer to such as in us are amenable to the 
will, together with some parts which act involuntarily — as the heart. 
This striped kind is the more complex in structure. 

Unstriped muscular tissue, as the more simple, may be first 
noticed. It is pale, translucent, and made up of a number of roundish 
or flattened fibres from the ru ' 0l to the ^^ of an inch in breadth, 
devoid of any limiting membrane, more or less fusiform in shape, 
and marked at intervals with oblong corpuscles. Each fibre is made 
up of bodies termed muscular fibre cells, of an oblong, flattened 
shape, of a granular substance, and containing an oval or rod-shaped 
nucleus. The nuclei become very distinct when the fibres are treated 
with dilute acetic acid. As well as forming fibres, those cells may 
be mixed up with other tissues, as, e.g., in the dermis (where some 
of them, by their contraction, may make hairs "stand on end" in 
the way before spoken of), or they may form broad layers of inter- 
lacing fibre-cells. They are never attached to bones. Sometimes 
they bifurcate at one end. 

Striped muscular tissue consists of fibres which are generally 
collected in larger or smaller bundles termed fasciculi (Fig. 76, A), 
each fasciculus being furnished by a membranous envelope sent in- 
wards from the sheath, or perimysium, which invests the whole 
muscle, except in the heart, where the fibres are naked. Each 
fibre (B) has a membranous transparent investment called the 
sarcolemma (Fig. 76, B e), which is of the nature of elastic tissue. 
The fibres average about T ^o- of an inch, but may be somewhat 
larger or much smaller. 

Within the wall of the sarcolemma, there may be at intervals elon- 
gated corpuscles, but the special characteristic of fibres of this tissue is 



* Fibrin is the name given to the soft, 
whitish, stringy substance, which maybe 
obtained from fresh blood by whipping 
it with fine rods. It is very like albu- 



men, but differs by its property of spon- 
taneous co-agulation. See the description 
of the blood, Chapter VII., § 2. 



126 



THE CAT. 



fCHAP. V. 



the appearance of a number of alternating, exceedingly regular, trans- 
verse markings, such striation depending on a regular arrangement of 
alternate parts with different refractive properties. Each striation 




Fig. 76.— Striped Muscular Tissue of the Cat, greatly magnified. 



A. Bundle or fasciculus of fibres. 

a. Cut end of a fibre. 

b. A fibre. 

c. A fibre broken up into its component fibrils. 

B. A fibre, with parts of two others. The fibre 

has been split at right angle to its long axis. 



One of the clefts. 

Investing membrane or sarcolemma, seen 

at a point of rupture. The sarcolemma is 

twisted, but not broken. 

Fibrilla of different magnitude (/, g, h,) very 

greatly enlarged. 



consists of a central narrow dark line (the septal line), on each side 
of which is a narrow transparent space (the septal zone), while be- 
tween the transverse striations is a much larger space (the inter- 
septal zone), and these larger parts constitute the main substance of 
the fibre and therefore of the muscle. The appearance, thus pre- 
sented is that of a number of opaque discs embedded, at regular 
intervals, in a more translucent substance. 

Faint indications of longitudinal division may also be detected, 
and after immersion in alcohol, or a weak solution of chromic acid, 
each fibre may be broken up into a number of very much more 
minute ones termed fibrillse (Fig. 76, C), each fibril still presenting 
the transverse striation. It is, however, by no means sure that each 
fibre is really made up of naturally distinct fibriUse, since, when 
treated with much diluted hydrochloric acid each fibre may be broken 
up into (B d) a number of thin discs, parallel to and coinciding with 
the transverse striations. In the heart, the fibres are bx^anched. 

§ 3. Muscular contraction (which takes place under certain 



chap, v.] THE CATS MUSCLES. 127 

conditions and excitations), not due to any mere physical or chemical 
change, but is a vital action. The capability of being acted on by 
such excitations is called irritability, and the special form of irrita- 
bility possessed by muscle is called contractility. 

This contractility may be seen to act in a single fibre, and it is by 
the simultaneous action of the fibres composing it that each muscle 
performs its proper function, and contracts as a whole. 

The change of shape referred to, is a temporary shortening of the 
fibres in length, with a consequent transverse enlargement. It is a 
familiar fact tbat when, in ourselves, the fore-arm is bent upwards a 
temporary swelling takes place on the front of the upper arm. This 
is due to the thickening which accompanies the shortening of the 
muscle mainly employed in effecting such movement. 

The contracted state of any muscle can only endure for a limited 
period, and cannot be repeated without an interval of rest, which 
must be greater according to the exhaustion induced by frequently 
repeated contractions. There is one muscle, however, which acts 
throughout the whole of life, the contractions being continually 
reiterated after short regular intervals of rest. This muscle is the 
heart, which takes its needful interval of repose after each contraction. 

Unstriped muscle contracts slowly and but slowly relaxes, while 
striped muscle can contract suddenly and be suddenly relaxed. In 
certain pathological states, as, e.g., in lockjaw, muscular contraction 
may be greatly prolonged. 

The amount of force with which a muscle contracts depends on 
the number of its fibres, but the length of the muscle determines the 
degree of shortening which can be effected. 

The irritability of muscular tissue persists for a certain period 
after death, which varies somewhat according to the cause of dissolu- 
tion — speedily disappearing after death from poisoning by noxious 
vapours, or from lightning, while occasionally it has been found in 
man to persist for twenty-four hours after death. Sixteen hours, 
however, is the ordinary limit, even of that part of the heart (the 
right auricle) which was called by Galen the " ultimum moriens/' 
on account of its long- enduring irritability. This property persists 
very much longer in cold-blooded animals, e.g., the frog. 

The agent which induces muscular contraction is called a stimulus, 
and there are various kinds of stimuli. 

Thus, there may be a direct stimulus, such as the application to 
the muscular fibres of a sharp-pointed body, or of an acid or some 
acrid substance, or by sudden heat or cold, or by a shock of 
electricity.* There may also be an indirect stimulus, i.e. when the 
excitation is applied not directly to the muscular tissue, but to the 
nerves distributed to it, or there may be a mental stimulus due to 
emotional excitement. Stimuli, physically equal, have a more 
powerful effect when acting on a muscle through a nerve, than 
when acting directly on the muscle itself. 

* The resistance of a muscle to elec- i transversely as it is in the direction of its 
trical conduction is seven times as great j length. 



128 



THE CAT. 



LCHAP. V. 



Shortly after death a peculiar rigidity of the muscles soonei or 
later sets in, which may be so intense that rupture of tissue will take 
place rather than change of posture, if force be applied to produce the 
latter. This is the death -stiffening, or rigor mortis. 

This rigidity does not alter the position in which the limbs may 
happen to be when it sets in.* It appears to be due to a solidifica- 
tion (coagulation) of the fluid substance of the muscular tissue. 

The occurrence of rigor mortis is a certain proof that death has 
taken place. 

§ 4. Muscular fibres being thus aggregated, as has been said, 
into various masses termed muscles, the number of these masses 
may be estimated at some 500 in the cat. They vary greatly in 
size, in weight, in form and in the arrangement of their fasciculi. 
Generally, the fasciculi are arranged longitudinally in a more or less 
parallel manner, and end by insertion side by side into a tendon ; 
but sometimes they radiate from a central band of dense fibrous 
tissue (or tendon) in a penniform or semi-penniform manner. Some- 
times they are arranged in a concentric manner round apertures, 
when they are called sphincters ; or in a cylindrical manner, as in 
the walls of the alimentary canal. They may have, as in the last 
named instance, no connexion with bone, but generally they are 
attached to bones which they employ (as we shall shortly see) as 
levers or fulcra, and are then generally inserted by means of those 
dense bands of parallel fibres of connective tissue called tendons. 

The fleshy mass of a muscle is called the belly, and there may be 
two such bellies with an intermediate tendon. Such a muscle is 
termed digastric. A muscle may arise by two or more heads, when 
it is called hi- or tri-cipital, as the case may be. 

That end of a muscle which is nearest to the central axis of the 
whole body, or to the root, or axis of the limb of which it forms 
part, is generally called its origin, or its "proximal end." The 
opposite extremity is generally called its insertion, or its " distal 
end." 

Muscles acting on bony levers produce definite motions of different 
kinds, according to the circumstances of their application. This 
difference of functions causes them to be distinguished by certain 
generic terms, each such term being applied to all such muscles as 
produce a motion of the kind denoted by the term. 

Thus, muscles which bend a joint so as to make the angle formed 
by two- long bones acute, or which move the digits towards the 
palmar or plantar surfaces of the feet, are termed flexors. Those 
the function of which is antagonistic to these are termed extensors. 

Some muscles attached to a long bone which is relatively fixed at 
one end, tend to make it describe the superficies of a cone, or a 
movement of circumduction. Such muscles are termed rotators. 



* Occasionally after death from cholera 
and yellow fever, distinct movements 
have been observed in the human sub- 



ject ; but these are probably due to so'me 
action of decomposition on parts of the 
nervous system. 



chap, v.] THE CAT'S MUSCLES. 129 

Some muscles move a bone away from a given axis, and are 
therefore termed abductors. Others tend to bring it towards such 
an axis, and such are called adductors. The epithets "protractors " 
"retractors, 11 "elevators" and "depressors, 11 (terms which require 
no explanation), are also sometimes made use of. 

There cannot, however, be any really good classification of muscles 
according to the functions they execute, because such functions may 
vary in different animals with regard to the very same muscle. 

§ 5. In considering the action of muscles, the support of the 
body may be first considered. The way in which this is affected 
varies of course with the posture it may assume. In standing, the 
basis of support afforded by the four paws is very wide, but the 
posture cannot be maintained when the muscles are inactive, on 
account of the flexibility of the joints. It is maintained by the 
normal contraction (tonicity) of the muscles, which, being placed on 
opposite sides of the body and of each supporting limb, antagonize 
each other, and so prevent the joints from flexing, and the body 
from consequently drooping, collapsing, and falling to the ground, 
as it does immediately when any sudden cause (such as a violent 
blow on the animal's head, or shot sent through its heart) suddenly 
suspends their action. 

During waking life, changes of posture, which tend to cause the 
centre of gravity to fall without the basis of support, are instinctively 
followed by compensating motions which have the effect of retaining 
it within such basis. Thus if the left fore-leg be extended outwards 
to the left, the body instinctively and simultaneously leans, or the 
tail is thrown, over to the right, and the extreme mobility of the 
tail in all directions is a great agent in maintaining the equilibrium 
of the body. 

In locomotion the limbs may be used either successively, as in 
walking, or simultaneously as in springing and running. In leaping, 
all the joints of the hind-limbs are bent, and these by their sudden 
unbending give impetus to the body. 

In walking, each leg alternately swings forward as a pendulum, 
the fore and hind-limb of each side being advanced successively and 
alternately with one of those of the opposite side, as e.g., 1st, left 
fore-leg ; 2nd, right hind-leg ; 3rd, right fore-leg ; 4th, left hind- 
leg. Even in walking, however, the impetus is imparted by the 
hinder limbs, the action of the fore-limbs being mainly that of 
support. 

The part of the foot applied to the ground by the cat does not 
answer to the sole of the human foot, but only to the toes ; the 
heel being raised much above the ground. Similarly in the fore- 
foot the wrist is raised and the digits alone support the body. On 
this account the cat's mode of progression is spoken of as 
digitigrade. 

As has been already said, the muscles generally act on the bones, 
making use of the latter as levers or eulcra. 

The levers used in the cat's body are of all the three orders 



130 THE CAT. [chap. v. 

known in mechanics. A " lever " consists of a rigid rod, movable 
in one plane round a point — the " fulcrum." 

The first order of levers is where the fulcrum is placed between 
the weight and the motive power. 

The second order is where the weight to be moved (or resistance 
to be overcome) is placed between the fulcrum and the power. 

The third order is where the power is applied between the fulcrum 
and the weight or resistance. 

In the action of the hind-legs of a cat which is lying on its back 
and scratching at an object with its hind claws, we have an example 
of the first order of levers. For thus the muscles of the calf, being 
attached to the tuberosity of the os calcis, act on the skeleton of the 
foot as on a rod resting against the distal end of the tibia as on a 
fulcrum. The other end of this rod (the claw-bearing part) pushes 
away any object against which it may strike. 

The same parts, as employed in walking, may serve as an example 
of the second class of levers. Thus considered, the earth will be 
the fulcrum, the weight to be moved (the body as resting on the 
tibia) being placed between it and the point of muscular attachment 
— that is where the motive power is applied. 

An example of the third order of levers is seen in the action of the 
cat in raising the fore-paw to strike or to wash the face or ear. Here 
the paw is the weight, and the fulcrum is the distal end of the humerus. 
The motive-power being applied in the intermediate space, viz. (as we 
shall see) at the attachment of the biceps muscle to the radius. 

§ 6. The classification of muscles follows naturally that of the 
parts of the skeleton. Thus we have — 

(a) Muscles of the exo-skeleton, the skin, and 

(b) Muscles of the end o- skeleton. 

To these it will be convenient to add a third category, namely, — 

(c) Muscles of the viscera. 

The exo-skeletal system of muscles may consist of smooth or striped 
fibres. Some are large and some very small. 

The endo-skeletal system is naturally divisible, like the endo- 
skeleton itself, into parts appertaining to the head, trunk, and tail 
(the axial portion), and parts belonging to the limbs (the appen- 
dicular portion). 

The viscero- skeletal system of muscles consists of the muscular 
fibres placed in the walls of the alimentary canal and in a variety of 
tubes or organs (such as the heart, bladder, &c.,) to be hereafter 
noticed in describing those parts. 

Since, however, the muscles of the first category are few in 
number, while those of the third may be better considered in treat- 
ing of the viscera they help to form, the best practical course here 
will be to consider the muscles according to the regions of the body 
to which they belong — the head and neck, the trunk and tail, and 
the limbs. 



chap, v.] THE CAT'S MUSCLES. 131 



MUSCLES OF THE HEAD AND BACK. 

| 7. The platysma myoides is a skin muscle which covers the 
side of the neck and face. Its facial part invests the bulbs of the 
vibrissa and long hairs of the eye-brows. 

The orbicularis oris is a sphincter muscle, its fibres extending 
round the mouth in the substance of the lips. The fibres of the 
upper and lower lip meeting at a symphysis at each angle of the 
mouth. It is very slightly developed, and is much interrupted 
medianly above, because the cat's upper lip is divided medianly 
into two lobes. 

The orbicularis palpebrarum is a thin muscle, the sphincter of the 
eye-lids, as it surrounds the eye beneath the skin. It is not attached 
to any bone except at the inner margin of the orbit, and its fibres 
are arranged concentrically so as to close the eyelids by their con- 
traction. This muscle adheres intimately to the skin. 

The occipito -frontalis is a thin, flat muscle, one portion of which 
is attached to the fascia of the occiput and temporal region, the other to 
the frontal region, and is connected with the orbicularis palpebrarum. 

The levator labii superioris alreque nasi is a rather large flat muscle 
which is connected above with the frontal portion of the foregoing, and 
thence descends to the upper lip and angle of the orbicularis oris. 

The levator angulioris (Fig. 77, c) is a small fleshy mass which arises 
beneath the infra-orbital foramen and descends to the outer ala of the 
nose and upper lip. 

The pyramidalis passes downwards from the frontal to the dorsum 
of the nose. 

Compressor naris. — This is a very faintly-marked muscle of fibres 
extending transversely over the cartilages of the nose. 

The zygomaticus (z) is a small muscle extending downwards from 
the malar close to the maxilla (when it is continuous with the zygo- 
mato-auricularis) to the orbicularis oris, near the angle of the mouth. 

The myrtiformis is a triangular, rather large muscle extending from 
the firm tissue enclosed in the upper lip to the side of the nose (my). 

The cat's ears are very movable, and can be strongly drawn back 
and folded down close to the head. 

A variety of small muscles are inserted into the cartilage of the 
external ear, or into a narrow, elongated cartilage called the scuti- 
form cartilage, which extends on the surface of the head obliquely 
forwards and inwards in front of each ear, and slides over the 
aponeurosis of the temporal muscle. 

Thefronto-auricularifa) is a small muscle extending from the 
orbit to the ear. 

Another is the temporo- auricular (to) which extends (beneath the 
front auricularis) from the hinder side of the orbit to the antitragus.* 

The maxillo- auricular (mo), slender and vertical, extends from the 
mandible behind the condyle to the outer side of the base of the concha. 

* For an explanation of the parts of the ear, see Chapter IX., § 26. 

k 2 



132 THE CAT, [chap. v. 

Yarious other muscles act on the ear, which it is not deemed 
necessary to describe in detail ; suffice it to say they may be grouped 
into muscles which tend to draw the external ear forwards, inwards, 
or backwards. Certain muscles pass even from the skin to the ear — 
the auriculo-cercicaUs from the skin of the front of the neck, and the 
auriculo- labial and the auriculo- submaxillary from the lips and from 
the skin beneath the lower-jaw. 

The zygomato-auricularis passes from the skin of the cheek and 
from the zygoma backwards to the pinna of the ear externally. It 
is in part continuous with the zygomaticus. It draws the ear forwards. 

The Attolentes auricalam are muscular bundles which pass from 
the mid- cranial region outwards to the pinna, so as by their con- 
traction to bring the two ears together. 

The retrahentes auriculam are various muscular (rd) bundles which 
come from the occiput and the cervical region to the pinna, and by 
their action draw it backwards. 

The eyeball, lying in its orbit, is held in place and moved by 
seven muscles. 

The first of this is the suspensor oculi, or "choanoid muscle/' 
which arises round the optic foramen, and thence expanding and 
embracing the eyeball, is inserted into rather the posterior surface ot 
the latter. Its fibres are directed longitudinally outwards, and it is 
more or less divisible into four parts — one superior, one inferior, one 
external, and one internal. 

External to this muscular cone are four straight and two oblique 
muscles of the orbit (Fig. 130). 

The four straight muscles, or recti, also arise round the optic 
foramen, and thence diverging, are respectively inserted into the 
upper, inner, lower, and outer sides of the eyeball, whence they are 
termed superior, interims, inferior, and extemus, respectively. They 
are inserted in front of the insertion of the suspensor oculi, and corre- 
spond with and are superimposed on the four portions of the latter. 

Each rectus muscle is a flattened band of parallel fibres, and pulls 
the eyeball by its contraction either upwards or inwards, or down- 
wards or outwards. By combining their actions variously, they 
can move it in any intermediate direction. 

The obliquus superior is also a long and slender muscle arising near 
the optic foramen. At the inner margin of the orbit its tendon passes 
through a fibro- cartilaginous ring (or pulley) attached to the frontal 
bone, and then bends backwards to be inserted between the upper 
and the external recti muscles. 

The obliquus inferior has no pulley, and is the only short muscle oi 
the orbit. It springs from the orbital plate of the maxilla near the 
lachrymal groove, and passing thence backwards, between the floor 
of the orbit and the rectus inferior, is inserted into the postero- 
external aspect of the eyeball. 

The two oblique muscles are so disposed as to draw the eyeball 
forwards and inwards when they act together, and to rotate it in 
different ways when they act successively. The upper oblique 



chap, v.] THE CAT'S MUSCLES. 133 

rotates it from without inwards and from below upwards, and the 
lower oblique acts in the reverse manner. 

We shall hereafter see that different nerves go to certain of these 
muscles. The choanoid muscle is supplied by the sixth nerve. 

The levator palpebrce is another long slender muscle arising near 
(above) the optic foramen. It is inserted into the upper eyelid, 
which it raises. No analogous muscle depresses the lower eyelid. 

The buccinator is a thin, delicate muscle extending between the 
alveolar margins of the jaws on each side of the mouth (Fig. 77, B). 
Its fibres cross each other near the middle of the muscle, and it is 
perforated by the duct of the parotid gland. It adjoins internally the 
mucous lining of the mouth ; externally, it is partly covered by the 
muscle next described. 

The masseter (31) is a short and very thick muscle (in two layers) 
which arises from the malar and under surface of the front part of 
the zygoma. Its fibres pass thence obliquely backwards (those of 
the outer layer, very obliquely), to be inserted into the concave outer 
surface of the ascending ramus of the mandible. Externally, this 
muscle is only covered by skin and fascia. Its action is to raise the 
lower jaw, and is therefore an important agent in mastication. 

Each temporalis (T) covers the side of the skull, almost meeting its 
fellow of the opposite side at the sinciput. Each arises in two layers, 
from the side of the skull (from the lambdoidal ridge to the postorbital 
process of the frontal) and being thick and fleshy, fills up the tem- 
poral fossa (to which it gives its name) within the zygoma. Its fibres 
converge (fan- wise) to its insertion into the coronoid process of the 
mandible. Its action raises the lower jaw, and thus enables the animal 
to take a very firm grip of any struggling prey it may have seized. 

The pterygoideu8 interims is a strong muscle which arises from the 
pterygoid fossa. Its fibres descend obliquely forward to its insertion 
in the inside of the angular part of the mandible. It is close to the 
masseter inferiorly, being only separated from the latter beneath the 
margin of the mandible, by aponeurosis. It acts with the masseter 
in raising the lower jaw. 

The pterygoideus externus arises from the outside of the pterygoid 
and pterygoid plate of the sphenoid, and is inserted into the inside of 
the neck of the mandibular condyle, and thence forwards to the 
orifice of the dental foramen. In its action it is also an elevator of 
the mandible, since though by its direction it tends to draw the 
mandible somewhat backwards, it cannot do so owing to the opposi- 
tion of the post-glenoid process. 

The digastric is a large muscle which arises from the skull behind the 
external auditory meatus, i.e., from the paroccipital. It is inserted into 
the inside of the anterior hair of the inferior margin of the mandible. 

The middle portion of the muscle is very aponeurotic internally, 
externally, and below. Its action is to depress the lower jaw and 
open the mouth (D). 

The stylo-hyoid (sty-h) is a longish muscle which descends from the 
mastoid process to the side of the hyoglossus. 



134 THE CAT. [chap. v. 

The stylo-glossus (sty-g) is very large. It arises from the stylo-hyal 
(and the ligament connecting it with the tympano-hyal), and the 
stylo-maxillary ligament, and thence passes to the side of the tongue. 

The stylo-pharyngeus arises from the stylo-hyal and tympano- 
hyal, and passes thence to the side of the pharynx. 

The mylo-hyoid is a flat muscle which passes from the inside of 
the mandible to the body of the hyoid. It unites with its fellow of 
the opposite side (in the middle line, beneath), the two together 
forming the muscular floor of the mouth. 

The genio-hyoid is narrow, and goes from inside the mandible, near 
the symphysis to the basi-hyal. 

The genio-hyoglossus is a flat, more or less triangular muscle which 
arises from inside the mandibular symphysis, and is inserted in a 
radiating manner from beneath the tongue towards its tip back to 
the basi-hyal. 

The hyoglossal is also a flat muscle passing upwards from each 
thyro-hyal to the side of the tongue. 

The thyro-hyal muscle is a flattened longitudinal one which unites 
the thyro-hyal with the chain of ossicles intervening between the 
tympano-hyal and basi-hyal. 

The sterno-hyoid arises on the deep (or inner) surface of the 
sternum, and is inserted into the basi-hyal (St. hy). 

The sterno-t/iyroid, arising close to the last noticed, is inserted into 
the thyroid cartilage of the larynx (St th). 

The thyro-hyoid is, as it were, a continuation of the sterno- 
thyroid, and proceeds on each side from the thyroid cartilage of the 
larynx to the thyro-hyal (Fig. 45, ty). 

These three last muscles all tend, directly or indirectly, to draw 
back the hyoid. 

The sierno- mastoid (Fig. 79, St m) arises from the side of the 
manubrium (beneath the anterior part of the pectoralis major), and 
passing forwards and upwards is inserted into the side of the skull 
just above the mastoid process. If one sterno-mastoid acts alone, it 
tends to rotate the muzzle towards the opposite side. If both act 
together, they tend to depress the head as a whole, and somewhat 
tilt up the muzzle. 

The cleiclo -mastoid arises from the clavicle, and is inserted into the 
mastoid process on the ventral side of the insertion of the more 
superficially passing sterno-mastoid. 

The scalenus secundus lies deeply at the side of the neck. It arises 
from the transverse processes of the 3rd, 4th, 5th, 6th, and 7th 
cervical vertebra?, and is inserted into the first rib (Fig. 79, sc 2 ). 

The scalenus primus (very much longer) arises mainly by strong 
but delicate tendons from the 4th and 5th cervical vertebrae, and 
is inserted into the 4th, 5th and 6th ribs near the sternum. It 
comes as it were out from the substance of the scalenus secundus, 
with which it is closely connected (sc l ). 

The action of the scaleni is to pull the ribs upwards and forwards, 
and so to help to expand the chest. 



chap, v.] THE CATS MUSCLES. 135 

The scaleni are entirely on the dorsal side of the axillary vessels 
and nerves. 

The rectus capitis anticus major proceeds from the transverse pro- 
cesses of all the cervical vertebrae to the basi-occipital. 

The rectus capitis anticus minor springs from the atlas, on its 
ventral aspect, and goes to the basi-occipital. 

The rectus lateralis proceeds from the transverse process of the 
atlas to the paroccipital portion of the skull. It is hardly separable 
from the obliquus capitis superior described below (Fig. 27, 4 ). 

The longus colli occupies the ventral aspect of the cervical and 
anterior dorsal regions. Its fibres extend between the transverse 
processes and bodies of the various vertebrae over which it passes, 
with the exception of the axis, and terminate anteriorly on the 
ventral surface of the atlas. It extends back to the body of the 
sixth dorsal vertebra. 

The rectus capitis posticus major passes from the neural spine of 
the axis to the occiput. 

The rectus capitis posticus minor goes from the neural arch to the 
occiput beneath the muscle last described. 

The obliquus capitis superior extends from the transverse process 
of the atlas, to the paroccipital region. It is a short muscle. 

The obliquus capitis inferior is very large. It arises from the neural 
spine of the axis, and is inserted into the transverse process of the atlas. 

The muscle named the splenitis is a large one arising from the 
whole length of the middle line of the neck, and from the anterior 
dorsal neural spines. It is inserted into the outer part of the 
lambdoidal ridge. 

The Complexus is a very large fleshy mass arising from the sides 
of the last five cervical vertebras. 

It is inserted into the occipital region beneath the splenius. 

Another muscle, called Complexus tertius, consists of a series of 
fleshy bundles which extend from the zygapophyses of the posterior 
cervical vertebrae, to the transverse process of the atlas. 

The constrictors of the pharynx are muscles which enclose the 
alimentary canal in the region of the throat, and form an elongated 
bag of three successive muscular divisions called respectively the 
inferior, middle, and superior. They spring respectively from the 
sides of the larynx, the hyoidean cornua, the pterygoid bones, and 
the mandible, and meeting in the middle line on the dorsal side cf 
the pharynx, are attached at their summit to the basi-occipital. 

The soft palate is formed in part by the help of two pairs of small 
muscles; (1) the levator palati descends from the sphenoid, petrous and 
tympanic bones. Its fibres radiating, in part meet those of its fellow of 
the opposite side, and in part lose themselves in the side of the throat. 
(2.) The circurnflexus palati arises from the skull externally to the 
foramen ovale, and externally to the origin of the levator palati. It 
then descends obliquely, and ends in a flattened tendon which 
passes inwards round the hamular process of the pterygoid, and 
expands within the velum palati. 



136 



TEE CAT. 



[CHAP. v. 



The muscles of the pharynx arid palate effect deglutition. As 
soon as any portion of food, or other object, is grasped by the 
superior muscle of the pharynx, its fibres and those of the lower 
pharyngeal muscles successively contract, so as to drive the sub- 
stance so grasped backwards towards the stomach. 



MUSCLES OF THE TRUNK AND TAIL. 

§ 8. The muscles of the back are arranged in successive layers. 




Fig. 77. — Muscles of Right Side of Fore-quarter. A rectangular cdt being made in the 

CEPHALO-HUM.ERAL, TO SHOW MUSCLES BENEATH. 



B. Buccinator. 

Ba. Brachialis anticus. 

C. Levator anguli oris. 
Ch. Cephalo-humeral. 
Cm. Cleido-mastoid. 

D l and D\ Two parts of deltoid. 

D. (Of head) digastric. 

Ed. External dorso-epitrochlear. 

Eo. External oblique. 

Fa. Fronto-auricular. 

La. Levator anguli scapulae. 

Ld. Latissimus dorsi. 

J.s. Levator scapulae. 

M. Masseter. 

Mo. Maxillo-auricular. 

My. Myrtiformis. 

Oo. Orbicularis oris. 

Op. Orbicularis palpebrarum. 



P 4 . Pectoralis. 
By. Pyramidalis. 
Ra. Retrahentes auriculam. 
Re. Rhomboideus capitis. 
Rm. Rhomboideus major. 
Smg. Serratus magnus. 
T. (Of head) temporal. 

T 1 and T z . Anterior and posterior parts of tra- 
pezius. 
Tr l , Tr 2 . Parts of triceps. 
To. Temporo-auricular. 
Z. Zygomaticus. 
Set. Scutiform cartilage 
Sty. g. Stylo-glossus. 
Sty. h. Stylo-hyoid. 
St. hy. Sterno-hyoid. 
St. th. Sterno-thyroid. 



Some of them help to retain the shoulder and pelvic girdles (and 
therefore also the limbs) in place. 

The most superficial dorsal muscle is a cutaneous muscle — or one 
intimately connected with the skin. It is called the Panniculus 
carnosus, and is one of the largest muscles of the body. It forms a 



chap, v.] THE CATS MUSCLES. 137 

fleshy sheet, which envelopes the anterior part of the back and the 
chest— being continued on into the neck and head as the platysma 
myoides already noticed. At its margin the panniculus ends in an 
aponeurosis, which connects it with parts adjacent. The muscular 
fibres converge to the axilla, being directed forwards and outwards 
to it on the chest, and forwards and downwards to it on the side of 
the back. It is inserted into the deeper fascia of the upper arm, 
passing in part on the inner side of the biceps muscle, and in part 
continuing on down to the wrist. 

The muscle by its contraction effects those twitching movements 
of which the cat's skin is capable. 

Next, beneath this cutaneous muscle is the trapezius, of which 
there are two parts, closely connected inferiorly, but dorsally, by a 
delicate fascia only. 

A. The hinder portion arises from the neural spines of the dorsal 
vertebras — from the second to the twelfth. It is inserted by 
strong fascia into the membrane which invests the external 
scapular muscles, the line of insertion passing obliquely across 
the spine of the scapula at a point situated about one-third of 
the length measured from its vertebral margin downwards, and 
dipping slightly beneath the insertion of the anterior part of 
the muscle (T 2 ). 

B. The anterior part arises from the fascia in the middle of the 
neck as far forwards as the hinder end of the origin of the 
cephalo-humeral, with which it is connected. Its origin 
extends backwards till within about half an inch of the origin 
of the posterior part. It is inserted' into the spine of the 
scapula, from the metacromion process upwards to the point of 
insertion into the scapular spine of the hinder portion of the 
trapezius, into the scapular spine, which insertion it slightly 
overlaps (T 1 ). 

The latissimus clorsi is an* exceedingly large sheet of muscle which 
takes origin from the neural spines of the vertebras, from fifth dorsal 
to the fourth lumbar — its origin from the lumbar vertebras being by 
fascia only. It is overlapped for almost the anterior half of its 
origin by the posterior part of the trapezius (Ld). 

Its fibres converge to a tendon which, after blending with that of 
the teres major, is inserted into the inner side of the shaft of the 
humerus below the lesser tuberosity. Virtually at its anterior end 
it blends with adjacent fibres of the fourth part of the pectoralis, 
and is then inserted into fascia in the neighbourhood of the 
axilla. Before its insertion it gives off a muscle — the inner dorso- 
epitrovhkar — which descends, and blending with the smaller external 
dorso-epitrochlear is inserted into fascia on the inner side of the 
olecranon. Its action is to pull the arm backwards, or, if the arm 
be fixed, to bring the body forwards. It thus gives much aid in 
climbing (Fig. 81, ide). 

The external dorso-epitrochlear. — This is a slender muscle 
(Fig. 77, ed), which takes origin from fascia outside the spine of the 



138 



THE CAT. 



scapula, between the hindermost and uppermost part of the deltoid, 
and the posterior end of the insertion of the trapezius. Elending 
with the internal dorso-epiti'ochlear, it is inserted as above stated. 

The serratus posticus anterior arises by fascia from the mid- 
line of the back, and is inserted by very thin and faintly marked 
muscular digitations, into the outer surfaces of the ribs, from the 
second to the twelfth — the digitations inclining downwards and 
very much backwards. Posteriorly it is over-lapped by the next 
muscle to be noticed. 

The serratus posticus posterior arises from the fascia of the middle 
of the back, and is inserted by six digitations into the outside of the 
eighth, ninth, tenth, eleventh, and twelfth ribs. The digitations 
are inclined downwards and very slightly forwards. Anteriorly it 
overlaps the hinder part of the serratus posticus anterior. 

A membrane called the " vertebral aponeurosis," is continuous 
with the serratus posticus posterior, and passing forwards between 
the muscles of the shoulder and those of the trunk, it also binds 
down the great muscle to be next described. 

Erector spina?. — Under this title is included a very large and 
complex muscular mass occupying the groove which exists on each 
side of the dorsum of the skeleton, between the neural spines and 
the ribs at the point where the latter are much arched upwards. 
It is divided into two parts, one being nearer to, the other farther 
from the neural spines. Each of these two parts extends forwards 
towards the neck from the common origin of both in the sacral 



Sacro-lumbalis. — This' name designates that part of the erector 
spina? which is the more externally placed, and is attached to the 
ribs. It is a very thick muscle at its origin from the ilium and 
sacrum close to their line of junction. It is inserted into the 
lumbar transverse processes on their dorsal aspect and, by tendons, 
into all the ribs at their angles — the tendons becoming longer as the 
muscle advances forwards. The last portion, that inserted into the 
transverse process of the seventh cervical vertebra, is the represen- 
tative of a muscle called the cervicalis ascendens. 

Longissimus dor si is the term applied to the inner part of the 
erector spina?. It is much smaller posteriorly than the last described, 
but extends further forwards. It arises from the anterior margin of 
the ilium, and the fascia investing the erector spina? dorsally, and 
is inserted into the dorsal surface of the lumbar transverse pro- 
cesses, the metapophyses and the ribs on the dorsal side of their 
angles. 

The transversalis cervicis is the continuation of the last described 
muscle into the neck, where it is invested by firm, strong tendons into 
the transverse processes of the five last cervical vertebrae. 

The spinalis dorsi is really but an inner portion of the longissimus 
dorsi, and goes from the neural spines of the more posterior to those 
of the more anterior dorsal vertebra?. As continued on to the spine 
of the axis, it is called the spinalis colli. 



CHAP. V.] 



TEE CAT'S MUSCLES. 



139 



Other minor divisions of the erector spinae hear the names semi- 
spinalis, multifidus spina, rotatores spina, inter- spinales, and inter- 
transver sales, and have their fibres directed as follows : at first, from 
the transverse processes to the neural spines ; the second, from 
metapophyses (or the parts which serially correspond with the met- 




Fig. 78 
-Internal aspect of Sternum and Costal Cartilages- 
almost all removed. 



-Muscles of left side being 



No. 1 to 13. The ribs. 

V, VI. The fifth and sixth sternebrae. 

d. Diaphragm. 

e. Internal intercostals. 
i. External intercostals. 
io. Internal oblique. 

sm. Sterno-mastoid. 
s 2 . Scalenus secundus. 



ts. Triangularis sterni. 

sb. Xiphoid cartilage. 

The small figure below represents on one side 
the sternal ends of the cartilages of the eighth 
and ninth ribs, and on the other side the 
sockets (/) for the cartilages of the eighth 
and ninth of the other side. 



B.— Articulations of certain Costal Cartilages and Sternom. 



apophyses,) to neural laminae in front of them ; the third, from the 
transverse processes to , the neural laminae next in front of them ; 
the fourth, from neural spine to neural spine, and the fifth and last, 
from one transverse process to another. 

If these various muscles of both sides of the body act, they flex 
the spine vertically — as when the animal bounds along. If those of 



140 



THE GAT. 



[CHAP. V. 



one side act alone, the whole backbone is flexed towards the side of 
such action. 

The levator es costarum are small groups of fibres passing obliquely 
backwards from the dorsal transverse processes to the respective ribs 
at their proximal parts. 

Layers of fibres extending obliquely from rib to rib are called 
" intercostal muscles," and there are two sets of them, one inner, 
the other outer (Fig. 78). 

The external intercostals are more dorsally situated, since each 




Pig. 79.— Muscles of Ventral Surface of Trunk— the left Fore-limb and left Pectoral 
Muscles being removed. 



CM. Cleido-mastoid. 

Cv. Clavicle. 

.D 3 . Deltoid. 

Ed. External dorso-epitrochlear. 

Exo. External oblique. 

Id. Internal dorso-epitrochlear. 

Io. Internal oblique. 

Ld. Latissimus dorsi. 

P», P 2 , and P\ Pectoralis. 



R. Rectus abdominis. 
.Sc 1 . Scalenus primus. 
Sc 2 . Scalenus secundus. 
Shy. Stern o-hyoid. 
Sm. Serratus magnus. 
St 1 . Sternalis. 
St*. Second sternalis. 
St. m. Sterno-mastoid. 



such intercostal connects two ribs, all the way from their tubercles 
to their cartilages. Their fibres are directed backwards and down- 
wards (i). 

The internal intercostals have their fibres directed backwards and 
upwards, and the sheet of such fibres which connects each pair of 
ribs reaches from the sternum upwards as far as the angles of the 



chap, v.] THE CATS MUSCLES. 141 

ribs. The intercostal nerves and vessels are interposed between the 
two sets of intercostal muscles (<?). 

The triangularis sterni is the name given to a layer of muscle 
which diverges forwards to the cartilages of the ribs from the deep 
(inner) surface of the sternum (Fig. 78, ts). 

The diaphragm is (as has been before mentioned) a very impor- 
tant partly fibrous, partly muscular structure, which separates the 
thoracic and abdominal cavities. It forms a partition convex 
forwards and concave backwards, and is attached to the xiphoid 
cartilage, to several ribs, to the centra of the lumbar vertebrae, and 
to the aponeurosis, which invests the quadratus lumborum and 
psoas muscles.* At its circumference the diaphragm is muscular ; 
its central portion is tendinous. It is perforated for the passage of 
certain organs — namely, for the oesophagus and for two great blood- 
vessels called aorta and inferior vena cava. 

The muscles just enumerated aid the process of respiration as 
follows : — 

Apart from the elasticity of the substance of the lun^s, respiration 
is effected by the successive enlargement and contraction of the 
thoracic cavity. We have seen that the ribs are movably articu- 
lated to the vertebral column. They can be drawn forwards (and 
the cavity of the thorax can be in consequence enlarged) by the 
external intercostals and levatores costarum, but the main agent in 
this process is the contraction of the muscular fibres of the diaphragm 
resulting in a diminution of its convexity. Air rushes in to fill the 
thus enlarging cavity, and we thus have Inspiration. Expiration is 
effected by the drawing backwards of the ribs by the internal inter- 
costals and by the relaxation of the contraction of the fibres of the 
diaphragm, which in consequence resumes its more convex shape, 
and so contracts the thoracic cavity, a process further aided by the 
contraction of the muscles of the belly, the external and internal 
oblique, the rectus and transversalis. 

The abdominal region of the body is invested by three great sheets 
of muscle and membrane, which enclose and support the abdominal 
viscera — and tend by their contraction to expel the contents of such 
viscera and, as just said, indirectly to aid in respiration. 

The first of these muscles, the external oblique, arises by eight 
digitations from the eight hindmost ribs and from the lumbar fascia. 
Its fibres pass obliquely downwards, backwards and inwards (towards 
the mid- ventral line,) to be inserted by muscle and membrane into 
the brim of the pelvis — part of the membrane (or aponeurosis,) 
divides into the "external" and " internal " tendons. Between 
these tendons (of which the internal is the stronger,) an aperture is 
left called the " external abdominal ring," (through which certain 
structures pass,) bounded in front by what is called Poupart's 
ligament. 

This so-called " ligament '■ is really but a band of delicate fascia, 

* These are described amongst the muscles of the hind limb. 



142 THE CAT. [chap. v. 

which extends from the pubic symphysis to the anterior part of the 
ventral margin of the ilium. 

In front of the pelvis the muscle ends in aponeurosis, which meets 
that of its fellow of the opposite side in the mid-ventral common 
fascia, which extends forwards to about the fourth rib. It passes 
superficially to the rectus muscle, but its fascia is closely adherent to 
the surface of the rectus. 

The deeper abdominal muscle, the internal oblique, is another sheet 
partly muscular, partly membranous, but its fibres are directed 
downwards, forwards and inwards. It arises from the lumbar fascia — 
on the outer side of the erector spinae — from the entire ventral margin 
of the ilium and from the pubis. At its origin it leaves three aper- 
tures at the brim of the pelvis. Through the uppermost of these the 
psoas muscle passes out to the thigh. The next below is traversed by 
the great vessels, and through the lowest the spermatic cord makes its 
exit in the male. It is inserted inside the cartilages of the ribs, and, 
behind the thorax, joins with its fellow of the opposite side — its fascia 
passing on the ventral side of the rectus to about the middle of the 
abdomen, in front of which point it passes above the rectus. 

The deepest of the abdominal muscles, the transver satis, arises 
from the cartilages of the ribs behind the diaphragm, from the 
ventral margin of the ilium and from the fascia which invests the 
under side of the erector spin 33. It is therefore separated at its 
origin by a wide interval from the origin of the internal oblique ; 
the interval being occupied by the erector spinas and by fat. The 
muscular fibres of the transversalis extend vertically downwards 
(i.e., transversely to the long axis of the body,) to the margin of the 
rectus, within which its fascia extends — i.e., on the dorsal surface of 
the rectus. The abdominal nerves extend round the body between 
this muscle and the internal oblique. 

Rectus abdominis. — This is a long muscle which, arising from the 
symphysis pubis, runs forwards in contact with its fellow of the 
opposite side, to be inserted into the third rib, and thence on, by 
aponeurosis, to the second and first ribs. It is enclosed ventrally 
by the aponeuroses of the external and internal oblique from its 
origin to the middle of the abdomen. Thence forwards it is enclosed 
below by the aponeurosis of the external oblique, while above, it 
is invested by the aponeuroses of the internal oblique and trans- 
versalis (Fig. 79, jR). 

The rectus is separated from its fellow of the opposite side by 
a narrow interval, which is occupied by a tendinous cord — the linea 
alba. 

The fibres of the rectus are interrupted at intervals by very faintly 
marked transverse tendinous intersections. 

Sternalis. — This small muscle (St 1 ) arises from the anterior end 
of the rectus abdominis close to the sternum, at the third and fourth 
costal cartilages. It passes forwards and outwards, and is inserted 
into the first rib just ventrally to the insertion of the scalenus primus. 
A small second stern alis (St 2 ) extends from the outer border of 



chap, v.] THE CAT'S MUSCLES. 143 

the rectus, and passes outwards to be inserted between the fifth, and 
the sixth hindmost digitations of the serratus magnus, just behind 
the hinder end of the scalenus primus. 

External to the abdominal muscles the trunk is invested by an 
aponeurosis called the superficial fascia. At its posterior part this 
fascia is separable into two layers, the deeper of which adheres to 
Poupart's ligament, while the more superficial is (in the male) 
prolonged into the scrotum — surrounding the structures which pass 
from out the abdominal ring into that receptacle. 

Internal to the abdominal muscles, the abdomen is lined by a 
membrane called the fascia transver salts. It is pierced near its hinder 
margin by an opening called the internal abdominal ring, through 
which the spermatic cord passes in the male. 

Levator caudce externus. — This is the continuation backwards of 
the longissimus dorsi, and arises from the lumbar and sacral trans- 
verse processes, and is inserted by a succession of long, delicate 
tendons into the metapophysial parts of the caudal vertebra) suc- 
cessively. This and the following muscle bend the tail upwards. 

The levator caudcb iniernus. — This is the continuation backwards 
of the semi-spinalis, and is a yet more medianly- placed dorsal muscle. 
It is formed of a number of delicate, fleshy bellies and tendons, 
which connect the dorsal and lateral regions of successive caudal 
vertebrae. 

The pabo-coccygeus is a thin, flat muscle which arises from inside 
the pubis and goes to the ventral aspect of the third, fourth, and 
fifth caudal vertebrae. 

The ilio-coccygeus passes from the inner side of the ilium to the 
ventral surfaces of the fourth, fifth, sixth, and seventh caudal 
vertebrae. 

The sacro-coccijgeus arises (on each side) from the lateral part of 
the ventral surface of the sacrum, and from the sides of the ventral 
surface of the first eleven caudal vertebrae. It sends its tendons 
forth back along the' ventral surface and side of the tail to its 
extremity. 

The infra-coccygeus is situated in the mid- ventral line of the tail, 
thus connecting together its successive vertebrae. 
The above four muscles bend the tail downwards. 
The ischio-coccygeus is large and thick. It springs from the spine 
and internal surface of the ischium, and is inserted into the whole 
length of the transverse processes of the first four caudal vertebrae. 

Inter -transversarii caudce are small slips connecting laterally the 
successive caudal vertebrae. It takes origin from the transverse 
processes of the last sacral vertebra. 

This and the preceding muscle flex the tail laterally. 
The following muscles are found in the vicinity of the root of the 
tail, and are some of them connected therewith : — 

Levator scroti. — This is a cutaneous muscle which arises in the 
dorsum of the tail at about the fifth caudal vertebra, and becoming 
connected with the sphincter ani externus expands upon the scrotum 



144 THE CAT. [chap. v. 

(or upon the parts analogous in the female) as a delicate layer of 
cutaneous muscular fibres. 

The ischio-cavernosus is a small muscle arising from inside of the 
ischium a little below its tuberosity and ending in a tendinous 
expansion applied to a part hereafter to be described as the corpus 
cavernosum (Fig. 115). 

The caudo-cavernosus is a slender muscle which passes backwards 
from the under-surface of the root of the tail to the corpus caver- 
nosum between Cowper's glands. 

Transversus perencei. — This is a small but very distinct muscle 
which arises from the inner side of the ischium below its tuberosity. 
It joins its fellow of the opposite side in front of the anal aperture, 
being more or less united with the sphincter ani internus. 

The compressor urethrce is a muscle which springs from the inner 
side of the pubis, and divides into two portions, one passing above 
and in front of, and the other below and behind, the urethra. 
These portions end by meeting with corresponding divisions of the 
muscle of the opposite side of the pelvis. It is very large in the 
male, extending between the prostate and Cowper's glands. 

The ano-coccygeus arises (in the middle line) from beneath the 
second and third caudal vertebrae, and passes downwards and back- 
wards, expanding as it goes, to the upper part of the rectum. 

The recto-coccygeus arises from the upper lateral part of the 
rectum. It ascends, and, joining with its fellow of the opposite side, 
passes upwards and backwards between the two ano-coccygeus 
muscles to the under surfaces of the sixth and seventh caudal 
vertebrae. It is covered laterally by ilio-coccygeus and pubo- 
coccygeus. 

The sphincter ani externus surrounds the root of the tail, the 
anus, the anal pouches, and the external generative organs. It arises 
from the dorsum of the tail at about the fifth caudal vertebra. The 
anal pouches are two rounded sacs, each about as big as a pea, placed 
one on each side of the rectum close to the anus. 

The sphincter ani internus is a mass of fibres arranged circularly 
around the anus in front of the sphincter externus and more or less 
united with it, especially with the fibres which constrict the anal 
pouches. 

Thus just as the anterior end of the alimentary tube is surrounded 
by a sphincter muscle — the orbicularis oris — so is its posterior 
termination also surrounded by an analogous muscular constriction — 
the sphincter ani. 

This muscle is a more complete sphincter than its anterior 
analogue, since it is not (as that is) interrupted by any median 
notch. It is connected beneath with the transversus perenaei muscles 
at their median junction. Above, it is connected by a tendon with 
the caudal vertebrae at the root of the tail. 

A retractor penis muscle passes from the ventral aspect of the 
hinder end of the rectum, to the ventral surface of the penis towards 
its distal end. 



chap. v.J THE CAT'S MUSCLES. 145 

MUSCLES OF THE LIMBS. 
THE FORE-LIMB. 

§ 9. Serratus magnus. — This is a large sheet of muscle which 
arises by ten digitations (the anterior four being wider than the 
others) from the sternal aspect of the first ten ribs. It is inserted 
into the vertebral margin of the scapula. The sealeni muscles dip 
in between the second and third, and between the fourth and fifth 
digitations of this muscle. 

The levator anguli scapula is a second sheet of muscle similar to 
the preceding, and so closely connected with it that they can only 
be separated artificially. It is inserted into the scapula with the 
serratus magnus. It arises from the transverse processes of the last 
five cervical vertebrae. The combined insertion of this and the 
serratus extends along the whole vertebral margin of the scapula 
posteriorly from a point just in front of the insertion of the rhom- 
boideus capitis. 

The combined action of these two muscles is to suspend the body 
as in a hammock from the summits of the two fore-limbs. It aids 
also in any pushing action of the fore-limbs, and therefore in 
springing. 

The cleido-mastoid has been already described.* 
The rhomboideus major is a sheet of muscle which takes origin 
(beneath the trapezius) from the neural spines of the six hinder 
cervical and the four or five most anterior dorsal vertebrae. It is 
inserted into the vertebral margin of the scapula; its insertion 
extending forwards about half an inch in front of the vertebral end 
of the spine of the scapula. 

The rhomboideus capitis is a long, narrow muscle which arises 
from the lambdoidal ridge, and is inserted into the vertebral margin 
of the scapula, just in front of the insertion of the rhomboideus 
major, dipping in between the insertion of the last-named and that 
of the serratus magnus. 

Pectoralis. — This is a very large muscle which consists of five 
portions, all going from the sternum and sternal ends of the costal 
cartilages to the upper arm. No part goes to the coracoid. 

(1.) The most superficial part (Fig. 79,^) is a long, rather narrow, 
band of parallel fibres which arises from beneath the manu- 
brium and attachment of the first two costal cartilages. It is 
inserted partly into the fascia of the flexor surface of the fore- 
arm, but partly joins the cephalo-humeral . and is inserted 
with it. 
(2.) The second and largest part (p 2 ) arises from the manu- 
brium and sternum as far back as the fourth costal cartilage. 
It also arises from fascia just in front of the manubrium. It 
is inserted into the outer side of the deltoid ridge of the 

* See ante, p. 134. 



146 



THE CAT. 



[chap. v. 




-Dorsal (Extensor) Muscles of 
Fore-limb. 

A rnd. Abductor minimi digiti. 

An. Anconeus. 

B. Biceps. 

B a. Brachial] s anticus. 

D' and D z . Deltoid. 

E c d. Extensor communis digitorum. 

E c 1 . Extensor carpi radialis longior. 

E c 2 . Extensor carpi radialis brevior. 

Ex. Extensor indicis. 

E m d 1 , Em d' z , and E in d 3 . Extensor minimi 

digiti. 
E o p. Extensor ossis metacarpi pollicis. 
Feu. Flexor carpi ulnaris. 
F p d*. Flexor profundus digitorum. 
Is. Infra-spinatus. 
P 2 . Fectoralis. 
S I. Supinator longus. 
S sp. Supra-spinatus. 
T ma. Teres major. 
T mi. Teres minor. 
Tr l , % and *. Triceps 



Fig. 81.— Ventral (Flexor) Muscles of 
Fore-limb. 

B. Biceps. 

B a. Brachials anticus. 

C b. Coraco-brachialis. 

C h. Cephalo-liumeral. 

E c 1 . Extensor carpi radialis longior. 

E c 2 . Extensor carpi radialis brevior. 

F p d 5 . Flexor profundus digitorum. 

F r. Flexor carpi radialis. 

F s. d l and 2 . Flexor sublimis digitorum. 

F tt 1 and 3 . Flexor carpi ulnaris. 

I d. Internal dorso-epitrochlear. 

L d. Latissimus dorsi. 

P 3 and P*. Pectoralis. 

P I. Palmaris longus. ' 

Tp 1. Tension of palmaris longus, cut short to 

show the subjacent flexor tendons. 
P t. Pronator teres. 
S s. Sub-scapularis. 
»S' sp. Supra-spinatus. 
T via. Teres major. 
2Y 2 -5. Triceps. 



chap, v.] THE CATS MUSCLES. 147 

humerus, and extends down (between the biceps and brachialis 
anticus to the summit of the lowest third of the humerus. It 
is imperfectly divisible into two layers. The more superficial of 
these {p 2, A) arises from the more anterior part of the sternum, 
and goes to the lower part of the insertion, while the other part 
(p 2 B) both arises and is inserted for the whole length of the 
origin and insertion of the second part. 
(3.) The third part (p*) arises from the sternum between the 
second and sixth costal cartilages. It is inserted into the head 
of the humerus between the tuberosities by strong fascia closely 
connected with that of the supra-spinatus muscle. It is also 
inserted by muscular fibres for a short distance into the front 
of the humerus just below the great tuberosity. 
(4.) The fourth part is the most posterior in origin. It is long 
and narrow, and its fibres run more antero-posteriorly than do 
the others. It arises from the sternum between the fifth costal 
cartilage and the root of the xiphoid. Towards its insertion it 
blends with the ventral part of the latissimus dorsi, and some 
of its fibres are inserted into the fascia in the neighbourhood 
of the axilla. Its main insertion is (by strong fascia) into the 
inner side of the deltoid ridge of the humerus below, and on 
the inner side of the insertion of the third part. 
(5.) The fifth, and much the smallest part, is the most an- 
terior (p 5 ). It arises from the side of the manubrium, covered 
by, and more or less blended with, the second part of the 
pectoralis. It passes outwards, becoming slightly connected 
with the clavicle, and is inserted into the humerus just above 
the insertion of the second part. It may be called the sub- 
clavicualr part of the pectoralis. 
This muscle adducts the humerus, and enables the cat to give a 
powerful blow with the paw inwards. If the arm be fixed, it then 
tends to draw the body forwards or, in climbing, upwards. 

The cephalo-humeral is a large muscle which arises conterminously, 
and more or less blended with the anterior part of the trapezius. 
Its main part takes origin from the back of the skull and the lamb- 
doidal ridge, and from fascia in the middle of the neck (Fig. 77, Ch). 
It passes down outside the clavicle (with which it contracts a 
slight adhesion) and outside the biceps — covering the front of the 
upper arm. Near the elbow-joint it fuses with the brachialis 
anticus (passing to the outer side and front of the biceps), and is 
inserted into the coronoid process of the ulna, having first received 
an addition from the first part of the pectoralis. 

The third part of the deltoid fuses anteriorly with the cephalo- 
humeral. 

The deltoid consists of three portions : — (Fig. 80, D 2 ) a part which 
arises from the scapula between, and from, the acromion and met- 
acromion processes ; and (D 1 ) a part which arises from the hinder side 
of the scapular spine, conterminous with the insertion of the anterior 
part of the trapezius. 

L 2 



148 THE CAT. [chap. v. 

These two parts have a common insertion into the lower third of 
the flat deltoidal surface on the outer side of the humerus — external 
to the bicipital groove. 

The third part arises from the hinder side of the clavicle and 
fuses with the adjacent part of the cephalo- humeral. 

The levator clavicuke is a muscle which takes origin from the 
transverse process of the atlas. 

It is inserted into the end of the metacromion (between the first 
and second parts of the deltoid), being overlapped by the cephalo- 
humeral and, quite anteriorly, by the sterno-mastoid. 

The supra-spinatus forms a very large muscular mass, which 
projects much beyond the anterior margin of the scapula. It 
arises from, and occupies the supra-spinous fossa of the scapula, with 
anterior side of the spine and acromion. It is inserted into the 
upper margin of the great tuberosity. 

The infraspinatus occupies the infra-spinous fossa of the scapula 
(arising from its whole surface, including the hinder side of the 
scapular spine, acromion and metacromion), and is inserted into the 
concavity on the posterior part of the outer side of the great 
tuberosity. 

The teres minor arises from the lower half of the axillary margin 
of the scapula, and is inserted into the hinder margin of the great 
tuberosity, below the insertion of the infra- spinatus. 

The teres major is a much larger muscle which takes origin from 
the posterior a ogle of the scapula and »the upper third of its axillary 
margin. It is inserted below the lesser tuberosity by a strong 
tendon common to it and to the latissimus dorsi. 

The subscapularis occupies the whole inner surface of the scapula. 
Its fibres converge from this extensor origin and are inserted into 
the lesser tuberosity and capsular ligament of the head of the 
humerus. 

The supra-spinatus, infra-spin atus and teres minor rotate the limb 
outwards, or tend to draw it forwards and raise it. 

The subscapularis and teres major rotate the limb inwards, and 
tend to draw it backwards. 

The coraco-brachialis is a very short muscle which arises by a 
delicate tendon from the coracoid process of the scapula, and is 
inserted into the inner side of the humerus just below the insertion 
of the subscapularis (and mainly above that of the teres major,) 
between the biceps and the fourth head of the triceps (Fig. 81, Cb). 

The biceps arises by a tendon' which takes origin from the upper 
margin of the glenoid cavity of the scapula. Passing down it is 
inserted by a tendon into the tubercle of the radius (B). 

The brachialis anticus is a muscle placed on the outer side of the 
front aspect of the humerus, taking origin from the surface of that bone 
as high up as just below the insertion of the teres minor (Fig. 80, Ba). 

It passes down between the second p^rt of the pectoralis major, 
the triceps and the supinator longus, and is inserted into the coronoid 
process of the ulna, and into the ulna on the inner side of that 



chap, v.] THE CAT'S MUSCLES. 149 

process. At its upper part this muscle is closely connected with the 
tendon of insertion of the deltoid. 

The coraco-brachialis draws the arm a little forwards and upwards, 
the biceps and brachialis anticus flex the elbow-joint, which is 
extended by the following muscle. 

' The triceps. — This is an enormous muscle, consisting of five parts. 
(1.) The first part (Fig 80, Tr l ), takes origin from the summit of 
the outer, posterior part of the humerus, within the tendon of 
insertion of the teres minor. Passing downwards, it blends 
with the second part a little above the elbow. 
(2.) The second and largest part arises by a strong, broad tendon 
from the lower half of the axillary border of the scapula, 
between the subscapularis and teres minor ; after receiving the 
accession of the first part it is inserted by a strong tendon into 
the end of the olecranon. 
(3.) The third part takes origin from the upper part of the inner 
side of the shaft of the humerus, mainly below, but partly 
overlapped by, the tendon common to the teres major and latissi- 
mus dorsi. Passing downwards it soon blends with the fourth 
part. 
(4.) The fourth part takes origin from the whole upper surface of 
the humerus just below its head, — from the origin of the first 
part of the triceps externally, to the insertion of the coraco- 
brachialis internally. Passing downwards it receives the 
accession of the third part and is inserted into the olecranon. 
(5.) The fifth and much smallest part arises from just above the 
internal condyloid foramen, and from the bridge of bone 
bounding that foramen, down to the internal condyle. Passing 
obliquely backwards (Fig. 81, t'°) it is inserted into the inner 
margin of the olecranon. ' 
The anconeus is much larger than the fifth head of the triceps. 
It arises from a triangular surface (with the apex upwards,) on the 
lower half of the shaft of the humerus (especially towards the outer 
side of that bone,) its origin extending to the margins of the 
olecranal fossa and right down to the external condyle. The 
muscle lies between the first and third parts of the triceps, and is 
inserted into the whole of the fossa on the outside of the olecranon. 
The muscles of the fore-arm consist of pronators and supinators, 
flexors and extensors, and their names sufficiently indicate their actions. 
The pronator teres arises from the inner condyle and passes down 
obliquely to its insertion into about the middle third of the front of 
the radius. 

The flexor carpi radialis is long and narrow. It arises from the 
internal condyle of the humerus in common with the head of the 
flexor profundus, and is inserted into the proximal end of the 
palmar surface of the second metacarpal. 

The palmaris longus arises from the internal condyle, and passing 
down becomes tendinous at the wrist, and ends in an aponeurotic 
expansion (called the palmar fascia), which exhibits tendinous 



150 THE CAT. [chap, y 

thickenings, and finally invests the bases of the digits. Near the 
wrist it gives origin to the ulnar part of the flexor sublimis. 

Flexor sublimis digitorum or f^r/oratus. — This muscle consists of 
two distinct parts, each of which is inseparably connected with another 
muscle. 

The ulnar part of the flexor sublimis arises from the ulnar side 
of the palmaris longus close to the wrist. It ends in two tendons, 
which go to the fourth and fifth digits respectively (Fig. 81, Fsd 1 ). 

Its radial part arises from the surface of the ulnar part of the 
flexor profundus — from the upper part of its tendon. It divides 
into two small fleshy portions, the larger of which, gives origin to 
two delicate tendons which go to the index and third digits (Fsd 2 ). 

All these four tendons go to the second phalanx of their respec- 
tive digits, each splitting (before its insertion) to allow a tendon of 
the deep flexor (next to be described) to pass through, whence this 
flexor receives its second above-given denomination. 

The second portion of the radial part of the muscle ends in a very 
delicate tendon, which goes to the ulnar side of the pollex. 

The flexor profundus digitorum or flexor perf or ans. — This is a very 
complex muscle, which arises by five heads. 

(1.) The first of these arises from the internal condyle of the 
humerus, in common with the third head and with the humeral 
head of the flexor ulnaris. Passing down it ends in a tendon 
which gives off superficially the radial part of the flexor sublimis, 
while on its deep surface it receives the insertion of the mus- 
cular fibres of the second part. Its tendon fuses with the* main 
tendon at the wrist. 
(2.) The second part, which is large and fleshy, arises from the 
outer surface of the ulna — from near the wrist nearly to the 
end of the olecranon, and passing up at the olecranon inside both 
the flexor carpi ulnaris and the fifth part of the triceps. It is 
inserted into the deep surface of the tendons of the first part 
of the flexor profundus. 
(3 ) The third part arises from the internal condyle, in common 
with the first part, and is also connected with the fourth part 
some little distance below its origin. It ends in a rather 
delicate tendon, which joins the main tendon at the wrist. 
(4.) The fourth part arises from the internal condyle, in common 
with the flexor carpi radialis. It becomes connected with the 
third part, and further down, ends in a rather strong tendon 
which joins the main tendon at the same time as does that of 
the third part. 
(5.) The fifth part arises from the flexor surface of the radius 
between the supinator brevis and pronator quadratus, and is 
inserted into the common tendon (Fig. 81, Fpd 5 ). 
The common tendon divides into five small tendons, which go to 
the distal phalanges of the five digits. Each of these tendons, except 
that to the pollex, passes through the split before mentioned as 
existing in each corresponding tendon of the flexor sublimis. It 



chap, v.] TUB CATS MUSCLES. 151 

is on this account that the flexor profundus is also called the 
" perforans." 

The himbricales are small, worm-like muscles (whence their name), 
which arise from the palmar surface of the deep flexor tendons of 
the four outer digits, and are inserted into the sheaths of the 
extensor tendons on the dorsal aspect of the digits as follows : — 

One arises from the radial side of the tendon going to the index 
and is inserted into the radial side of the index. Another springs 
from the palmar surface of the tendon of the medius, and goes to the 
radial side of the medius ; the third springs from the palmar surface 
of the tendons of the third and fourth digits, and goes to the radial 
side of the fourth digit. The fourth and last arises from the radial 
side of the tendon going to the fifth digit, and is implanted also into 
the radial side of the fifth digit. 

The flexor carpi ulnaris arises hy two heads (separated hy the 
ulnar nerve), one from the inner condyle of the humerus, the other 
from the inner side of the olecranon, almost to its very extremity, 
so that it dips in under cover of the fifth part of the triceps. The 
humeral belly of this muscle is intimately connected with that head 
of the flexor profundus which gives origin to a part of the flexor 
sublimis. The two heads continue separate a considerable distance, 
and then unite and are inserted into the pisiforme and the fifth 
metacarpal. 

Pronator quadratus. — The fibres of this muscle extend obliquely 
downwards from the ulna to the radius, on the deep flexor surfaces 
of those bones for rather less than the lower half of each. 

Supinator longus. — This is a long and very slender muscle, which 
arises high up, very much above the external condyle, from the 
outer surface of the brachialis anticus, and from the middle third of 
the outer surface of the humerus. It is inserted into the outer side 
of the distal part of the radius (Fig. 81, SI). 

The extensor carpi radialis longior is also a long narrow muscle, 
which arises from the supinator ridge below the origin of the muscle 
last described, and is inserted into the dorsum of the second meta- 
carpal. 

The extensor carpi radialis brevior arises close beside and closely 
connected with the last. Also long and narrow, it ends in a tendon, 
which is implanted into the dorsum of the third metacarpal. 

Extensor communis digitorum. — This muscle takes origin from the 
external condyle of the humerus, and is more or less divisible into 
two parts. One part sends tendons to the second and third (or 
second, third, and fourth) digits, and the other to the fourth and 
fifth digits. Its tendons are inserted into the second and third 
phalanges of each of the four ulnar digits. 

The extensor minimi digiti is of about the same size as the last 
described muscle, arising in common with it and running down 
beside it. It soon divides into three parts, whereof the first and 
second are much more closely united together than they are to the 
third part. The first two parts arise in front of and somewhat 



152 THE CAT. [chap. v. 

within the third part, and at about the middle of the arm divide 
into two tendons. The more radial of these goes to the fourth digit, 
and the more external (the paw being prone) to the third digit. 
The third part arises highest up and superficially to the other parts. 
It ends in a tendon which runs deeply and (passing at the wrist 
through a separate synovial sheath) goes to the fifth digit (Fig. 80). 

The extensor indicts et extensor secundi internodii pollicis is a 
very long and slender muscle, which springs from the outer margin 
of the ulna, for almost its whole length , and from the outside of the 
olecranon, being there covered in by the anconeus. Tt ends in two 
delicate tendons, which go to the pollex and index digits respectively. 

The extensor ossis metacarpi pollicis is a large muscle arising from 
a great part of the extensor surface of both the radius and the ulna, 
and from the interosseous ligament. It is inserted into the first 
metacarpal. Its origin on the ulna extends almost up to the 
olecranon. On the radius it is conterminous with the insertion of the 
supinator brevis. 

The extensor carpi ulnaris takes origin from the external condyle 
of the humerus (below the other muscles there arising), and is 
inserted, by a very strong tendon, into the fifth metacarpal. 

The supinator brevis is a rather deeply placed muscle, which 
comes from the outer condyle of the humerus and the upper part of 
the ulna, and is inserted into the radius, wrapping it round some- 
what from behind. 

The muscles of the fore-paw are numerous but small. The pollex 
(which has no perforated flexor) is provided with a flexor brevis, 
which extends from the trapezium, the trapezoides, and adjacent 
deep palmar fascia, to be inserted into the base of the proximal 
phalanx of the pollex. 

Opponens pollicis. — This is a very small muscle, closely connected 
with the last-named. Similar in origin, it is inserted into the 
metacarpal of the pollex. 

An abductor brevis pollicis passes from the trapezium and annular 
ligament of the wrist to the proximal phalanx of the pollex. 

A flexor brevis minimi digiti arises from the annular ligament and 
unciforme, and is inserted into base of the first phalanx of the fifth digit. 

A few fibres with a similar origin, but inserted into the fifth met?- 
carpal, constitute an opponens minimi digiti. 

The adductor minimi digiti is a relatively considerable muscle, 
which arises from the palmar fascia at the root of the pollex, and is 
inserted into the first phalanx of the fifth digit. 

An abductor minimi digiti arises from the outer side of the pisi- 
forme, and is inserted by a long and delicate tendon into the ulnar 
side of the proximal phalanx of the fifth digit (Fig. 80, Amd). 

The interossei are small muscles which arise from the sides of the 
metacarpals and go to the sides of the proximal phalanges. When 
the back of the paw is looked at (the other muscles being dissected 
off) four interossei, called dorsal, are to be seen as follows : one on 
each side of the third digit, one on the radial side of the index, and 



chap, v.] THE CATS MUSCLES. 153 

one on the ulnar side of the fourth digit. When the palmar 
surface of the paw is looked at, a double interosseus is to be seen on 
the ulnar side of the index ; one is also to be seen on the radial side 
of the fifth digit, and we also see those which were partly visible 
when the paw was viewed dorsally. We thus learn that those seen 
dorsally on either side of the third digit have a common belly on 
the palmar surface, as also that the dorsal interosseus, which appears 
on the ulnar side of the fourth digit, has a palmar division going 
to the radial side of the fourth digit. In this way each digit (apart 
from the pollex) has a pair of interossei, except the fifth digit, which 
only has an interosseus muscle on its radial side. 

These little muscles act mainly as short flexors, but also somewhat 
as extensors. Each is a double-bellied muscle which divides, and 
is doubly inserted : one insertion being into the first phalanx and 
sesamoid beneath it, and the other extending upwards towards the 
sheath of the extensor tendons, and so helping to retract the claws. 

The muscles of the anterior region of the trunk, and of the fore- 
limbs, are invested by a membrane called the superficial fascia , and a 
synovial membrane is placed in the subcutaneous tissue which 
invests the acromion, olecranon, and joints of the paw. 

A deeper, stronger fascia is placed in the axilla, which descends 
the arm and becomes continuous with the annular ligaments of the 
wrist, beneath which pass the flexor and extensor tendons, their 
passage being facilitated by the presence of synovial membranes. 

The strong palmar fascia, in which the palmaris longus ends, has 
already been mentioned. 

As to the stretch of muscles over the segments of the pectoral 
limb, we have seen that some muscles which are inserted into the 
shoulder- girdle proceed from the trunk, as the trapezius; others pro- 
ceed from the shoulder- girdle to the upper arm, as the deltoid; others 
from the upper-arm to the fore-arm, as the brachialis anticus ; and, 
finally, others from the fore-arm to the hand, as the deep flexors 
of the digits. But there are also muscles which pass direct from the 
trunk to the upper- arm, as the latissimus dorsi ; or direct from the 
shoulder to the fore- arm, as the biceps ; or direct from the upper- 
arm to the hand, as do a great number of the muscles inserted into 
the latter — the flexores, carpi radialis andulnaris and the flexor sub- 
limis digitorum, arising, as we have seen, from the inner, or ulnar, 
condyle of the humerus ; and the extensores carpi radialis longior 
et brevior, the extensor communis digitorum and extensor carpi 
ulnaris, arising, on the contrary, from its outer, or radial, condyle. 
The extensors, as well as the flexors of the digits, all take origin 
in the arm and not in the hand itself. 

As to the direction of the muscles of the arm the long flexors of 
the pollex and other digits are not oblique, but arise on the same 
side of the limb as that on which they are distributed. 

The extensors of the outer digits cross the extensors of the thumb. 

AS to the NUMBER OF MUSCLES WHICH MAY BE INSERTED INTO A 

single digit, we see that the ideal perfection of having both a flexor 



154 



THE CAT. 



[chap. v. 



GfltXJ 



and an extensor inserted into every segment from the metacarpal to 
the last phalanx is only attained in the "* index and the digitus 
minimus. 

Thus in these digits the metacarpal bones are flexed by the flexor 
carpi radialis and flexor carpi ulnaris respectively, while no other 
metacarpal has a separate flexor. They are extended by the 

extensores carpi radialis longior 
and ulnaris respectively. The 
first phalanx of each is flexed 
by the interossei, and extended 
by the extensores indicis and 
minimi digiti respectively. The 
second phalanx of each is flexed 
by the flexor perforatus and 
extended by the extensor com- 
munis digitorum. The ultimate 
phalanx in each is flexed by 
the flexor peribrans and ex- 
tended by subdivisions of the 
interossei (aided by the lum- 
bricales), which join the ex- 
tensor sheath and are finally 
inserted into the distal phalanx. 



MUSCLES OF THE HIND LIMB. 




Fig. 82.— Superficial Muscles of Thigh. 

B. Biceps femoris. 

G. Gastrocnemius. 

G wx l and G mx 2 . Gluteus maximus. 

M. Semi-membranosus. 

S. Sartorius. 

T. Semi-tendinosus. 

T a. Tibialis anticus. 

Tvf. Tensor vaginae femoris. 



§ 10. The muscles of the 
hip and thigh, though mainly 
taking origin from the pelvis 
and leg bones, yet partly arise 
from the loins. 

The gluteus maximus con- 
sists of a great sheet of muscle 
and tendinous aponeurosis, and is more or less divisible into two parts : 
one arises, by fascia, from the membrane covering the sacral region 
dorsally, and, by some muscular fibres, from the sacrum itself ; the 
other part arises, by muscular fibres, from the first two caudal vertebrae. 
The first part is inserted into the great trochanter, at the base of its 
hinder outer part. The second part of the gluteus maximus is in- 
serted into the femur below of the great trochanter, by means of a 
sheet of fascia (the fascia lata), which invests the thigh, dipping in 
between the adductor and the vastus externus, and descending right 
down to the external condyle of the femur. 

The tensor vaginae femoris is a large thick muscle which arises from 
the anterior end and anterior half of the ventral margin of the ilium, 
and from the dense fascia intervening between it and the first part 
of the gluteus maximus. It is inserted into the fascia lata, which dips 
in 'as before said) between the adductor and the vastus externus. 



CHAP. V.] 



THE CATS MUSCLES. 



155 



The glutens medius is very large and fleshy, 
whole outer surface of the ilium, and from the 



It arises from 
fascia between 



the 
the 




Fig. 83.— A. Deep Muscles ©e Thigh, Biceps, 
B. Muscles and Tendons of 

A. Adductor. 
A m d. Abductor minimi Higiti. 

B. Biceps femoris cut short. 
E b d. Extensor brevis digitorum. 
E I d Extensor longus digitorum. 
F I. Fascia lata. 
F I h. Flexor longus flallucis. 
G l , G 3 , G*. Gastrocnemius. 
Gd. Gluteus medius. 
G mx l and 2 . Gluteus maximus. 
M. Semi-membranosus. 
P b. Peroneus brevis. 
P I. Peroneus longus. 



and. Fascia lata, cut and REFLECTEr* 
Outer Side of Ankle. 

P qd. Peroneus quinti digiti 

Pin. Plantaris. 

Ps. Psoas. 

Qf. Quadratus femoris 

S. Sartorius. 

Sol. Soleus. 

T. Semi-tendinosus. 

T a. Tibialis anticus. 

Ts. Tenuissimus. 

Tvf. Tensor vaginae femoris. 

The rectus femoris is shown in the angle 
between Gd and Vex. 



gluteus maximus and the tensor vaginae femoris. It is inserted into 
the great trochanter. 



156 THE CAT. [chap. v. 

The gluteus minimus arises from the ventral part of the outer 
surface of the ilium hehind and beneath the muscle last described; 
also from the anterior part of the ischium, above the acetabulum. It 
is inserted also into the great trochanter. 

The gluteus quartus is a very small and delicate muscle which 
arises in front of the acetabulum just outside the origin of the rectus 
femoris. It is inserted into the front of the femur on the inner side 
of the great trochanter, i.e., to the middle of the anterior inter- 
trochanteric line, passing down between the vasti. 

The piriformis takes origin from the ventral surface of the 
sacrum. It passes out of the great sacro-sciatic notch (superficially 
to the great sciatic nerve, and in close apposition to and somewhat 
connected with the hinder surface of the gluteus minimus), and is 
inserted into the great trochanter within the insertion of the gluteus 
medius. This and the following muscles, up to and including the 
quadratus femoris, rotate the hind limb outwards. 

The obturator externum arises from the outer surface of the ob- 
turator membrane and the bony margin surrounding it. Passing at 
first upwards and backwards, it ends in a strong tendon which turns 
outwards, and is inserted into the trochanteric fossa. 

The obturator interims arises from the inner surface of the ob- 
turator membrane and its bony frame. Its fibres converge to a 
tendon which ascends, curves round the ischium and passes out- 
wards and forwards to be inserted into the trochanteric fossa. 

The gemellus anterior is a very small muscle which arises from the 
spine of the ischium and is inserted into the anterior margin of the 
tendon of the obturator internus. 

The gemellus posterior is a muscle similar to the last in size and 
insertion, but which takes origin from the tuberosity of the ischium. 

The quadratus femoris is a muscle which proceeds from the 
tuberosity of the ischium and the margin of the ischium below it, to 
the posterior intertrochanteric line and posterior surface of the 
femur at the lower end of the great trochanter (Fig. 83, A, Qf). 

Psoas magnus is a large muscle arising from the interior of the 
trunk and passing out beneath the brim of the pelvis. It arises 
beside the diaphragm from the transverse processes of all the 
lumbar vertebrse, and is inserted into the lesser trochanter of the 
femur (Ps). 

Iliacus. — This muscle is represented by fibres which arise from 
the inner surface of the ilium and blend with the psoas magnus. 

The psoas parvus is but a subdivision of the psoas magnus, which 
subdivision ends in a strong tendon inserted into the ilio-pectineal 
eminence. 

The quadratics lumborum is a muscle which arises (by a strong 
tendinous origin) from the outer margin of the ilium, half an inch 
behind its anterior end. Its fibres become closely connected with 
those of the psoas magnus, along the under surface of the lumbar 
transverse processes and onwards to the body of the twelfth dorsal 
vertebra. 



CHAP. V.J 



TEE CATS MUSCLES. 



157 



These three muscles bend the pelvis or thigh upon the body, and 
vice versa, and are of great use in running, bounding, and climbing. 

The pectineas is a muscle which descends from the most anterior 
part of the symphysis pubis and ventral part of the brim of the pelvis 
to be inserted into the ridge which descends from the lesser tro- 
chanter to the linea supra, and into the linea itself. It is a small 
thin muscle, yet it extends half way down the thigh. 

Except at its uppermost part it is inserted by fascia which is 
much connected with the muscle next described. 

The adductor is a very large muscular mass, and is more or less 




Fig. 84. — Muscles of inside of Thigh, Sartorius and Gracilis being cut and reflected. 

A. Adductor. 

A i. Abductor indicis. 

E x b. Extensor brevis digitorum. 



E I d. Extensor longus digitorum. 

F I d. Flexor longus digitorum. 

F I h. Flexor longus hallucis. 

G' 2 . Gastrocnemius. 

Gr. Gracilis. 

M. Semi-membranosus. 

Pec. Pectineus. 

Pin. Planteris. 



Pop. Popliteus. 

Ps. Psoas. 

Pf. Rectus feinoris. 

S. Sartorius. 

Sol. Soleus. 

T. Semi-tendinosus. 

T a. Tibialis anticus. 

T p. Tibialis posticus. 

T v f. Tensor vaginae femoris. 

V in. Vastus internus. 



incompletely divisible into several parts. It arises from the symphysis 
pubis, and from the pubis and ischium at each end of the symphysis. 
It is inserted by muscle into the whole length of the linea aspera, 
and into the space between the inferior bifurcation of the linea 
aspera, at the lower end, of the back of the femur. It is closely 
connected at its insertion with the inner head of the gastrocnemius. 

The sartorius arises from the most anterior part of the ventral 
margin of the ilium. It spreads out into a broad muscular sheet 
which invests the front and antero-intemal part of the thigh, and 



158 THE CAT. [ohap, v. 

is ultimately inserted into the ligament of the patella and Internal 
tuberosity of the tibia. Some of its muscular fibres extend down to 
the tibia below its inner tuberosity. 

The gracilis is a wide, flat, muscular sheet, which arises by 
tendinous fascia from beneath the symphysis pubis, and is similarly 
inserted into the inner side of the tibia, its broad insertion being 
overlapped by the sartorius. Like the preceding muscle it is a 
flexor of the leg on the thigh. 

Semi-tendinosus. — This is along, subcylindrical muscle, which arises 
by tendon and fascia from the tuberosity of the ischium, beneath 
and a little behind the origin of the biceps femoris. It is inserted 
partly into the tendinous sheath of fascia which goes to the inner 
side of the tibia, and partly, by a very strong tendon, into the front 
of the tibia, about half an inch below the patella (Fig. 84, T). 

The semi-membranosus is very thick and fleshy, and more or less 
double. It arises from the tuberosity of the ischium, and from the 
ramus of the ischium below the tuberosity down to the symphysis. 
It is much united in its course and insertion with the adductor. It 
is inserted into the inner condyle of the femur and above it up to the 
insertion of the adductor, and also by a strong tendon (which passes 
beneath the internal lateral ligament of the knee) into the internal 
tuberosity of the tibia (Fig. 74, sm). The part with the latter insertion 
arises within the origin of the other part, the muscle being near its 
origin folded on itself, with the opening of the fold forwards. The 
two parts are entirely separable for the last inch of their course. The 
part inserted into the inner condyle is closely connected with the 
internal head of the gastrocnemius. 

Biceps femoris. — This is an enormous sheet of muscle, the fibres of 
which expand in a fan -like manner (Fig. 82, B). It arises (by muscle 
and strong tendon) from the tuberosity of the ischium, somewhat 
between the origin of the semi-tendinosus and semi-membranosus, but 
anterior to both. It is inserted by a tendinous fascia into the outer 
side of the leg from the top of the knee-joint nearly to the heel, but 
it is especially inserted into the outer tuberosity of the tibia. 

The three muscles last described are called the hamstring muscles, 
and are powerful flexors of the leg. 

Tenuissimus (Fig. 83). — This most delicate muscle arises from the 
caudal vertebrae at the front end of the second part of the gluteus 
maximus, with which it is intimately united. Passing down beneath 
the gluteus maximus and inside the biceps, it ends by blending with 
the inner surface of the latter muscle close to the anterior end of its 
inferior margin. 

The quadriceps extensor, or great extensor of the leg, consists of 
four parts, which have a common insertion into the tendon of the 
patella, and, through it, into the tuberosity of the tibia. 

The first part is the rectus femoris, and arises from the hinder 
part of the ventral margin of the ilium, and, by a tendon, from the 
antero -superior margin of the acetabulum. 

The second part, or vastus extermis, is of enormous size, wrapping 



CHAP. V.] 



TEE CATS MUSCLES. 



159 



round the rectus femoris in front. It 
arises from the whole outer surface of 
the femur and great trochanter. 

The third part, or vastus iniernus, 
springs from the inner side and front of 
the femur, right up to the capsular liga- 
ment (Fig. 84). 

The fourth part, or crureas, arises from 
the lower half of the front of the femur. 

The leg has five long muscles in front 
and seven behind. 

The tibialis anticus takes origin from 
the fossa on the outer side of the upper 
fourth of the tibia, from the adjacent part 
of the fibula, and from the intervening 
inter-osseous ligament. It is inserted by 
a strong tendon into the dorsum of the 
rudimentary first metatarsal. It covers 
over the upper third of the extensor 
longus digitorum, and its action is to 
bend the foot forwards and inwards on 
the leg. 

The extensor longus digitorum pedis 
arises by a strong tendon from the pit on 
the femur, which is situate just outside the 
outer margin of the groove for the patella. 
At the ankle it passes through a strong 
tendinous loop devoted to it alone, and 
which loop is attached to a concavity 
on the upper surface of the os calcis, in 
front of (below) the astragalus. Before 
passing through the loop it is already 
divided into four tendons, which go to 
the exterior sheaths of the four digits. 

The peroneus longus is a very notable 
muscle which takes origin from the head 
of the fibula around the attachment of 
the external lateral ligament. It ends 
by a tendon which passes down in front 
of the external malleolus in a special 
groove in the front of the fibula, which 
groove is bridged over by a tendinous 
arch lined by synovial membrane. 
Passing superficially to the tendons of 
the two muscles next described, it dips 
in beneath the deepest plantar muscles, 
and traversing the channel formed for 
it by the groove beneath the cuboid and 
the peculiar process of the ento-cuneiforme, 



Gin 




ig. 85. — Flexor Muscles of 
Leg, the Gastrocnemics, Plax- 
taris and Sole us being removed. 

A 1 and A 2 . Accessories. 

Fb. Flexor brevis digitorum, 

cut and reflected. 
Fid. Flexor longus digitorum. 
F I h. Flexor longus hallucis. 
Gex. External head of Gastro- 
cnemius. 
Gin Internal head of ditto. 
L 1 , 2 , and 3 . Lumbrical muscles. 
Oc. Os Calcis cut short off. 
P b. Peroneus brevis. 
P I. Peroneus longus. 
Pop. Popliteus. 
P qd. Peroneus quinti digiti. 
Sol Soleus. 
Tfp. Tendon of deep flexor 

muscle . 
Tp. Tibialis posticus. 



160 THE CAT. [chap. v. 

it ends by being implanted into the inner end of that groove close tc 
and at least indirectly connected with the minute innermost meta- 
tarsal — that of the hallux. 

This muscle aids in walking by pulling up the inner side of the 
foot, and indirectly pressing the distal ends of the inner long meta- 
tarsals upon the ground as a fulcrum. 

The peroneus brevis arises from the front and outer side of the 
lower half (or more) of the fibula — except close to the external 
malleolus. It ends in a tendon which passes behind the external 
malleolus, and beneath the tendon of the peroneus longus, and is 
inserted into the proximal end of the fifth metatarsal. 

The peroneus quint i digiti springs from the upper and outer half 
of the fibula, and ends by a slender tendon which passes, in a 
synovial sheath, behind the external malleolus, and is inserted into 
the dorsum of the proximal phalanx of the minimus digit. 

The extensor brevis digitorum pedis is a short muscle which takes 
origin from the concavity on the distal part of the dorsum of the 
os calcis and from the dorsum of the cuboid. It divides into three 
bellies, each of which ends in a strong tendon. The innermost tendon 
divides at about the distal end of the metatarsals, one division going 
to the proximal phalanx of the index, the other to that of the third 
digit. 

The second tendon similarly divides, and goes to the third and 
fourth digits. 

The third and outermost tendon goes to the fourth digit only. 

Thus the fifth digit receives no tendon from this muscle. 

Of the muscles behind the leg the largest is the gastrocnemius. 
Two heads respectively arise from the two sesamoids, which are 
placed one behind each of the two condyles of the femur. 

Another (third) head arises from the ligamentum patellae in 
common with the plantaris. 

A fourth head (Fig. 83, 4 ) arises from the fascia investing the 
peronei muscles and fibula. The third and fourth heads, with the 
head from the sesamoid behind the external condyle, unite inextric- 
ably with the plantaris. The head from the sesamoid behind the 
internal condyle remains long distinct, but ultimately unites with the 
other heads which, all having united, end below in a strong tendon 
— the tendo Achillis — which is inserted into the hinder part of the 
tuberosity of the os calcis, superficially to the insertion of the 
soleus. Close to the heel, the tendon passes to the peroneal side of 
that of the plantaris, the latter there appearing and becoming 
superficial to it (Fig. 84). 

The plantaris arises from the ligamentum patellae in common with 
the third head of the gastrocnemius. Below this origin it is closely 
mixed up with the outer parts of the gastrocnemius — though well 
distinguished from the inner part of the latter. It forms below 
a strong tendon, which becomes visible just above the tuberosity 
of the os calcis on the tibial side of the tendo Achillis. It then 
expands and glides over the pulley-like surface of the calcaneal 



chap, v.] THE CAT'S MUSCLES. 161 

tuberosity — its passage becoming facilitated by synovial membrane. 
It ends in the plantar fascia, which invests the under surface of 
the foot and gives origin to the flexor brevis digitorum. 

The sokus arises from the summit of the back part of the 
fibula and is inserted into the tuberosity of the os calcis beneath 
(i.e., covered in by) the tendo Achillis. 

These three muscles raise the heel and are great agents in 
jumping. 

The popliteus is a short oblique muscle, which takes origin by 
a thick tendon from and just outside the external condyle of the 
femur. It is inserted on the posterior surface of the tibia, above 
the oblique line and conterminous with the origins of the tibialis 
posticus and flexor longus hallucis (Fig. 85). 

Flexor brevis digitorum or perforatus. — This muscle takes origin 
from the plantar surface of the plantar fascia of the plantaris. It 
is made up of four small muscles, placed side by side, which send 
tendons to the four digits ; the muscle and tendon going to the fifth 
digit being the most slender. These tendons go to the second pha- 
langes, but each splits opposite the proximal phalanx to allow a tendon 
of the flexor longus to pass through the perforation thus formed. 

The flexor longus digitorum pedis or preforans is rather small, and 
arises from the hinder surface of the tibia, below the popliteus, 
from the summit of the fibula and from the intermuscular fascia 
between it and the tibialis posticus. It ends below in a tendon 
which passes down a groove behind — or rather on the inner side 
of — the internal malleolus. This groove is lined by a separate 
synovial membrane, and is just behind that for the tibialis posticus. 
The tendon passes into the plantar region and ends by dividing 
into four tendons, which are inserted into the distal phalanges of 
the digits after perforating the tendons of the flexor brevis. 

The flexor longus hallucis is a large muscle which takes origin 
from the back of the fibula and tibia and interosseous ligament 
— below and external to the origin of the last described muscle. It 
ends in a tendon which passes in a synovial sheath behind the 
internal malleolus, and beneath the sustentaculum tali of the os 
calcis in a deep groove. It ends by coalescing with the tendon of 
the flexor longus digitorum. It is much connected with the peronei 
which border it externally. 

Lumbricales. — There are three of these muscles in the hind-paw, 
and they resemble those of the fore-paw. One passes from between 
the deep flexor tendons of the index and third digits to the tibial 
side of the third digit. The second goes from between the deep 
tendons of the third and fourth digits to the tibial side of the 
fourth digit, and the third goes from the deep flexor tendon of 
the fifth digit to the tibial side of the same digit. 

Accessorius. — This is a very small muscle of two bellies, which 
arise on the plantar surface of the conjoined deep flexor tendon, 
and end by two delicate tendons, which join the tendons of the flexor 
brevis, going to the third and fourth digits (Fig. 85). 



162 THE CAT. [chap. v. 

Tibialis posticus. — This muscie lies deeply and takes origin from 
the hinder side of the tibia beneath the popliteus, and from the 
hinder surface of the head of the fibula. It ends below in a tendon 
which passes down the internal malleolus in a special groove placed 
close to, but in front of, the groove for the flexor longus digitorum. 
It ends by being inserted into the prominence at the hinder part of 
the inner border of the naviculare. This muscle is naturally quite 
covered in by the flexor longus digitorum, save where its tendon 
appears in front of that of the last named muscle. 

The abductor indicis is a small muscle arising from the plantar 
fascia and tarsus at the root of the rudimentary hallux, and is 
implanted into the tibial side of the proximal phalanx of the index. 

Opponens minimi digiti. — This is a narrow muscular band which 
arises from the plantar fascia at the root of the index digit, and is 
inserted into the metatarsal of the fifth digit. 

Abductor digiti minimi. — This arises from the plantar surface of 
the os calcis, and is inserted by a delicate tendon into the peroneal 
side of the proximal phalanx of the fifth digit. 

The inter ossei are a set of small muscular bundles — two to each 
digit, except the rudimentary hallux. They all take origin from 
the plantar surface of the proximal ends of the metatarsals, and 
pass upon either side of these bones to their distal ends. There 
they are inserted partly into the sesamoid bones (placed one beneath 
the distal end of each metatarsal) and partly they ascend (like those 
of the fore-paw) to be inserted into the extensor tendons. 

The pelvic limb is, like the rest of the body, clothed with a 
subcutaneous superficial fascia. In the thigh this takes the name 
of fascia lata, and is very dense (especially on the outer side of the 
limb) and sends down expansions between the muscles, one larger 
expansion penetrating to the linea aspera. 

The aponeurosis of the leg is continuous at the ankle with the 
anterior annular ligament, beneath which pass the extensor tendons. 

The internal annular ligament passes from the inner malleolus to 
the heel, and transmits the flexor tendons. 

The external lateral ligament passes from the outer malleolus to 
the heel, and transmits the tendons of the peroneus longus and 
peroneus brevis. 

In the foot, as in the hand, synovial bursse facilitate the passage 
of the tendons. 

As to the stretch of muscles over the segments of the pelvic 
limb, there are certain muscles inserted into the pelvic girdle and 
proceeding to it from the trunk — as the abdominal muscles and psoas 
parvus; others proceed from the pelvic girdle to the thigh, as the 
glutei ; others from the thigh to the leg, as vastus externus and 
internus, and the crureus ; and finally, others from the leg to the 
foot, as the deep flexors of the digits. 

But muscles may pass directly from the trunk to the thigh, as the 
psoas ; or directly from the pelvic girdle to the leg, as the ham-string 
muscles; or directly from the thigh to the foot, as the gastrocnemius. 



chap, v.] THE CATS MUSCLES. 163 

None of the muscles, however, which go to the digits arise from 
the femur, except the extensor longus digitorum pedis, while, on the 
contrary, some of the flexors and extensors — as the flexor brevis and 
the extensor brevis — take origin not in the leg but in the foot 
itself. 

As to the NUMBER OF MUSCLES WHICH MAY BE INSERTED INTO 

A single digit, we see that the ideal perfection of having both a 
flexor and an extensor inserted into every segment from the meta- 
tarsal to the last phalanx is only nearly attained in the digitus 
minimus. Thus its metatarsal is flexed by the peroneus brevis and 
extended by the peroneus tertius. Its first phalanx is flexed by the 
interosseus, and is more or less extended by (though it receives no 
tendon from) the extensor brevis. The second phalanx is flexed 
by the flexor brevis or perforatus, and is extended by the extensor 
digitorum longus. The third phalanx is flexed by the perforans or 
flexor longus, and more or less imperfectly by the interosseous and 
lumbrical muscle. 

Besides these muscles the digitus minimus has also an abductor 
and an opponens. 

§ 11. The differences between 'the muscles of the fore arid hind 
limbs are the following : — The flexors and extensors of the pelvic 
limb arise lower down than do those of the thoracic limb. Nothing 
in the fore limb answers to the peroneus longus of the hind 
limb, while nothing in the leg answers to the supinator longus or 
to the extensores carpi radialis longior and brevior of the arm. 
In the fore-paw there is no accessorius, and its perforated muscle 
is a long one, while in the hind-paw it is a short muscle. There 
is a second (short) extensor of the digits in the hind-paw, there is 
none in the fore-paw. There is no long extensor tendon to the index 
and fourth digits of the hind-paw. The deep flexor tendons spring 
from one tendon in the fore-paw, from the conjoined tendons of 
two muscles in the hind- paw. 

In the foot, the hallux being a mere rudiment, it has not muscles 
corresponding with those which the pollex has. Again, the hind-paw 
has that very peculiar muscle — the accessorius — to which nothing 
in the fore-paw appears to correspond. 

The agreements between the muscles of the two limbs may 
be expressed as follows : — The supra and infra- spin atus and teres 
minor are inserted into the pre-axial tuberosity, while the psoas 
and iliacus are inserted into the pre-axial trochanter. The sub- 
scapularis and teres major are inserted into the post-axial tuberosity, 
the glutei are inserted into the post- axial trochanter. 

The triceps is the great extensor of the arm and the quadriceps 
of the leg. The biceps of the arm seems to be represented by the 
gracilis and sartorius of the leg. The coraco-brachialis corresponds 
with the adductor ; the extensor ossis metacarpi pollicis with the 
tibialis anticus ; the flexor carpi ulnaris with the peroneus brevis, 
and possibly also with the soleus and the gastrocnemius; the 
extensor carpi ulnaris with the peroneus tertius ; the flexor carpi 

m 2 



164 THE CAT. [chap. v. 

radialis with the tibialis posticus ; the flexor digitorum profundus 
with the flexor longus digitorum ; the flexor digitorum suhlimis 
with the flexor brevis digitorum ; the extensor communis with the 
extensor longus digitorum ; the palmaris longus with the plantaris ; 
the pronator teres with the popliteus ; while the lumbricales and 
interossei generally correspond in spite of the slight differences 
already noted. 

§ 12. Considered independently of the bony skeleton, the 
muscular system of the cat may, as its simplest expression, be con- 
ceived as a fleshy envelope of the body which takes the form, 
ventrally, of three superimposed layers (the fibres being directed 
differently in each layer), and dorsally, of a number of very various 
longitudinal bundles, ending in tendons directed more or less 
obliquely forwards. In the tail the envelope consists of longitudinal 
bundles, which, below as well as above, end in tendons directed 
more or less obliquely backwards. In the head, the muscular 
envelope becomes complicated for the hyoid, jaws, and organs of 
sense. The muscles of the limbs may be conceived as sheaths of 
fibres forming a median and two lateral groups of muscles, both on 
the extensor and flexor surfaces of each limb, with special modifica- 
tions and subdivisions where each limb becomes subdivided into its 
terminal digits. 



CHAPTEE VI. 



THE CAT S ALIMENTARY SYSTEM. 



§ 1. In the first chapter of 1 this work it was pointed out that the 
great function of sustentation * was in part brought about by the 
process of alimentation and in part by secretion. 

Alimentation is effected by the reception of new elements into the 
very ultimate substance, or parenchyma, of the body. This process 
is called assimilation, and consists in the transformation of what is 
immediately external to the parenchyma into the parenchyma itself 
— the change of the flesh and blood of other creatures into cat-flesh 
.and cat-blood. As to this process, science can only say that it is 
performed, the ultimate " how " of the transformation is an altogether 
insoluble problem. 

Nevertheless certain physical properties and conditions, to be 
adverted to shortly, help us to understand various digestive and 
other processes which serve and lead up to the final act of assimila- 
tion. Assimilation is always effected from a fluid medium derived 
from the food ; but in order that the food should be able to supply 
the body with such a medium, it must, sooner or later after its 
reception, undergo a certain process of preparation. Thus the 
whole process of nourishing 'the body by food — the process of 
alimentation — is made up of three subordinate processes : (1) the 
reception of the food, (2) its preparation, and (3) its assimilation. 

But that the life of the cat may be maintained, nutriment is by 
no means the only requisite. It is also necessary that a certain tem- 
perature should be maintained by a constant process of oxygenation 
of the body's substance, which temperature may be greatly above or 
somewhat below that of the surrounding air. Thus two classes of 
supply are called for : (1) matter for the nutrition of the tissues, 
(2) matter to serve for the production of warmth. Both these 
matters together constitute what is known as " food." 

§ 2. As to the kinds of food required by the animal we are 
considering, it must evidently be supplied with what contains the 
requisite materials for forming all its tissues, since all of them, even 
the very bones, are being slowly changed and renewed piecemeal 

* See ante, p. 1 0. 



166 THE CAT. [chap. vi. 

(luring life. Now every tissue, as we liave seen, can ultimately be 
reduced to oxygen, hydrogen and carbon, with or without nitrogen, 
and a few other elementary substances, in greater or less 
quantity. But let the cat be supplied, however plentifully, with 
these elements in whatever forms or combinations which are merely 
chemical, and it would none the less infallibly starve ; for it has no 
power of building up from inorganic matter, the very complex sub- 
stances of which its bod} 7 is formed. It absolutely requires to be 
supplied with compounds which have been ready formed for it by 
other creatures — it must feed on living or recently dead animal or 
vegetable substances. Such inorganic matters as water with the 
salts which may be dissolved within it, do, however, form part of 
its food. 

The organic substances on which it lives, may, like its own 
tissues, be divided into the nitrogenous and the non-nitrogenous, 
and there are two sets of each of these kinds. 

One set consists of albuminoid substances, such as the blood and 
flesh of the animals on which it may prey. Their connective tissues, 
cartilage, and bone, are examples of gelatinoid substances, and of 
such the second set of nitrogenous foods consists. 

Oleaginous substances (or fats and oils) and amylaceous substances 
— sugar, starch, and gum — are the two sets of non-nitrogenous 
foods. The last set are mainly of vegetable origin, but there is a. 
sort of starch (glycogen) in the livers of animals, while muscle has 
a sugar of its own (inosite), and there is a sugar of milk. 

Much oxygen (as we shall hereafter see) is also received into 
the body by the lungs in respiration. 

The products of that waste of the tissues which is inseparable 
from the wear and tear of life (and which necessitates the acquisition 
of food) are eliminated in various ways by the lungs, kidneys, and 
skin, and the undigested residue of what has been eaten is cast forth 
from the alimentary canal itself. 

The process of nutrition effected by food is, in the early life of 
the animal, greatly in excess of waste, but at maturity a prac- 
tical equilibrium is established, which is maintained till, with the 
advance of age, the balance at first existing becomes reversed. 

§ 3. As has been said, secretion is closely connected with alimen- 
tation. That it must be so will clearly appear if we reflect that 
" secretion " is an action by which certain portions of the body 
extract from the blood new substances (the various secretions) 
which do not exist as such within it, and that " nutrition " (the 
culmination of the alimentary process) is an action by which 
certain portions of the body extract from the blood new substances 
(the various tissue-substances) which do not exist as such within it. 
Every part of the cat's body which can be nourished' must necessarily 
have this power or the cat could not repair the effects of its own 
waste when adult, or "grow" during immaturity. In "nutrition," 
however, the formed product enters into the composition of the 
body itself, while in secretion this is not (directly at least) the case 



wm 



chap, vi.] THE CATS ALIMENTARY SYSTEM. 167 

— the product being discharged from some surface external or 
internal. 

But in fact it is not the blood alone which is in all cases the direct 
source of nutrition, since the blood has the power of replenishing 
itself and repairing its losses out of the fluids obtained from the 
food. The intimate way in which assimilation takes place, is 
named intussusception, to distinguish it from any growth which may 
take place by mere external addition — as when a crystal grows, 
while suspended in a suitable medium, by the deposition of fresh 
matter on its surface. 

Another process, which is ancillary to nutrition and secretion, is 
termed absorption, which is the generic term applied to the intro- 
duction into any tissue of the body, of substances external to it, 
and thus nutrition, or assimilation, itself is, in fact, one form of 
absorption. The process of absorption is aided by the physical 
properties termed end osmosis and exosmosis, terms which denote the 
passage of fluids in opposite directions through dead animal 
membranes ; different fluids, when thus divided, tending to pass 
through to the other side of such membranes with different degrees 
of rapidity. 

Dialysis is the term used to denote this movement of transfusion, 
irrespective of its direction, and therefore includes both endosmosis 
and exosmosis. 

§ 4. It has been found that different substances may be arranged 
in two classes according to their diffusibility, and that this division 
coincides with certain other characters which the two classes, termed 
respectively crystalloids and colloids, present. All crystalloid 
bodies are crystallisable ones. When dry, they are hard, rigid, and 
quickly soluble ; their solutions are never viscous, they are always 
more or less sapid, and they are highly diffusible. Colloids do not 
crystallize, and when dry they are tough. They dissolve slowly, and 
their solutions are more or less viscous ; they are insipid, and they 
diffuse wdth difficulty. Albuminoid and gelatinoid substances are 
colloids. 

Dialysis doubtless takes place in the living body : as in secretion, 
nutrition, and absorption, and it is possible that some such process 
may be the cause antecedent to muscular contraction. All salts and 
other crystalloid matters, whether useful, indifferent, or hurtful, 
readily find their way into the substance of the body from the 
alimentary canal, but, as w T e shall see later, this ready penetration 
of very diffusible substances is not the same thing as true intestinal 
absorption where a selective power is manifested. This latter active 
kind of absorption is, as has been already said, analogous to 
secretion. 

§ 5. The consideration of the distinctions which exist between 
colloids and crystalloids leads us to the last preliminary considera- 
tion, namely, to that of the process of digestion. This process 
consists in the reduction of food to a state in which it can be readily 
taken up into the system, and since it cannot be so taken up except 



168 THE CAT. [chap. vi. 

by passing through the substance of limiting membranes, it is 
obvious that this process must be synonymous with an increase of 
the food's diffusibility, a quality acquired in part by a change in 
its chemical composition, in part by its very minute subdivision. 

Minute subdivision is produced by mastication, by the contraction 
of the walls of the alimentary canal, and by the influence of fluids 
poured into that canal, and which reduce the fatty matter of the 
food to the condition of an emulsion. 

Diffusibility is produced by a transformation of colloids into 
crystalloids, starchy matters being changed into that highly soluble 
crystalloid, sugar; and the albuminoid and gelatinoid substances, 
being transformed into albumen-peptone and gelatin-peptone, both 
of which are capable of ready absorption. These transformations 
are effected by the agency of certain fluids which different parts 
of the alimentary organs secrete and pour into the alimentary 
tract. 

These facts and considerations throw a certain light on the process 
of alimentation. But any explanations to be thence derived are 
manifestly most incomplete, because the very living membrane itself 
can cause changes in the fluid itself as it passes through it, and the 
living particles of parenchyma exercise a certain power of choice 
with respect to the contents of the fluids in contact with them. 
Such particles are not passive bodies, but active, living agents, and 
their action no one has yet really explained. 

§ 6. The processes of alimentation may then be summarized as 
follows : — 

To support life by due repair of waste, and the maintenance of 
the necessary body temperature, food is required of such a nature as 
to furnish the substance of the tissues, and to serve as fuel. This 
food must be minutely comminuted, or rendered soluble by me- 
chanical action, and by the influence of suitable fluids. When this 
process of digestion has been accomplished, the nourishing product 
becomes more or less completely absorbed, and, passing into the 
blood-stream, regenerates it, and through it supplies every part of 
the frame with fresh material, which is taken up by internal 
assimilation or intussusception, and transformed into the substance 
of the living body — the non-nutritio us, non- absorbed residua being 
discharged. 

This great function is subserved by an elaborate apparatus, 
commonly known as the stomach, intestine, &c, with their annexed 
organs. It may be shortly described as a convoluted tube of 
different capacity in different parts, passing from one end of the 
body to the other, with two terminal apertures and with muscular 
walls, the fibres of which are so arranged as, by their regular, 
alternate contraction and relaxation, to drive the contents of the 
tube onwards from its anterior to its posterior termination. 

The anterior part of the tube is enlarged and specially modified 
to serve for the reception of the food, its subdivision and preparatory 
moistening by certain fluids. This is the buccal cavity, or mouth, 



■i 



chap, vi.] TEE CATS ALIMENTARY SYSTEM. 169 

with its lips, jaws, teeth, tongue, palate, fauces, and salivary or 
spittle glands. 

[Next follows the part immediately behind the mouth, called 
the pharynx, which opens into the gullet or oesophagus, which 
perforates the diaphragm and leads into that dilated chamber the 
stomach. To this immediately succeeds the small, and afterwards 
the large, intestine — with a blind off-shoot, the cmcum, at their point 
of junction — the whole terminating by that part of the canal which 
is called the rectum. Annexed to the canal (pouring fluids into it 
of great importance to the alimentary function) are the pancreas and 
the liver, and that part of this whole complex system of organs 
which is behind the diaphragm, lies suspended in the abdominal 
civity by a delicate and very complexly-folded membrane, the 
peritoneum. 

As we have already seen * in the second chapter, the skin which 
is reflected inwards at the mouth, nostrils, and other body apertures, 
assumes a soft and delicate texture with a moistened surface, and is 
known as mucous membrane. We have also seen that the wdiole of 
the alimentary tube, and the structures opening into it, are lined by 
this membrane. The epithelium, which everywhere invests its 
surface, may be of the columnar form (as in the stomach and 
intestine), or spheroidal, as in the linings of the alimentary glands. 
Its corium may contain abundant connective tissue (with many 
elastic fibres), as in the gullet, or there may be but little, as in the 
walls of the stomach. It may be so richly supplied with minute 
blood-vessels, immediately beneath the basement membrane, as to 
seem almost made up of them, while its deepest layer often consists 
of non-striated muscular fibres. It is also richly supplied with 
nerves, but their number varies greatly in different regions, as does 
the sensibility of the parts. 

As to the form and nature of the prominences — villi, papillae, 
&c. — which beset its surface, they also are very different in different 
parts of the alimentary tube. 

§ 7. A fluid, named mucus, is almost universally present wdiere 
mucous membrane exists, and gives its name to that membrane. 
It is an alkaline or neutral secretion, viscid, colourless, and clear 
or slightly turbid. It consists mainly of water, but has from 4 to 
6 per cent, of solid matter, and contains corpuscles. Its special 
constituent is an albuminoid substance named mucin, which is the 
cause of its viscidity. Mucus is formed by the epithelial cells of 
mucous membrane, but especially by certain branching or "race- 
mose" glands. Its use is to preserve the moisture of the membrane, 
and also to protect it from the dissolving action of the various 
digesting fluids. It doubtless also helps the senses of taste and 
smell, partly by preserving the moisture of the surface of the organs 
of those senses ; partlv by helping to dissolve the various sapid 
matters. 

* See ante, p. 25. 



170 



THE CAT 



[CHAP. VI. 



§ 8. The cat's mouth is bounded externally by tbe lips, which 
form a single fold around the lower jaw, and two folds, separated 
by a median notch, around the upper jaw. Inside the lips, folds of 
membrane called frama, proceed inwards, and bind them to the 
gums, which are masses of dense fibrous tissue investing the alveolar 
margins of the jaw-bones and covered by mucous membrane of a 

smooth and highly vascular 
character. Laterally, the 
mouth is bounded by the 
cheeks; it is bounded below 
by the tongue and the soft 
parts which connect the 
tongue with the mandible. 
Above, it is bounded by 
the palate within the upper 
alveolar margin. The lips 
and cheeks are composed 
of muscles and skin (as 
already described), together 
with blood-vessels, nerves, 
and * fat. The mucous 
lining of the mouth abounds 
in small glands, of which 
those inside the lips are 
called " labial" and those 
inside the cheeks " buccal." 
On the palate, the mucous 
membrane, where it invests 
the bones, is raised into 
about eight (Fig. 86) curved, 
transverse, permanent ridges or rugce. Beyond the bones, the palate 
is continued for a long distance as " the soft palate " (investing the 
muscles already noted), and which hangs down from the hinder edge 
of the palatine bones like a curtain, and is therefore called the 
velum palati. The palate abounds in small " palatine glands." 
The middle part of the free edge of the velum presents a slightly 
marked notch. Two folds of membrane descend, diverging as they 
descend, from either end of the velum (see Fig. 87, p, and in 
front of t). These folds form what is called the anterior and 
posterior " pillars of the fauces/' or the isthmus faucium. The term 
" fauces " is used to denote that posterior aperture of the mouth 
which is bounded laterally by these pillars, above by the velum, and 
below by a structure rising up behind the tongue, and hereafter 
to be described as the " epiglottis." 

Between the anterior and posterior pillar of the fauces on each 
side is a large horizontally-placed crescentic depression (with numer- 
ous openings of follicles * scattered over its floor), called a tonsil 
(Fig. 87, t). The use of the tonsils is unknown. 

* A "follicle " is a minute simple bag-shaped gland. 




Fig 86.— Palate. 

ap. Anterior palatine foramen. 

In this view the small upper molar is we 1 ! seen, as 
also the inner tubercle of the sectorial tooth 



CHAP. VI.] 



TEE CAT'S ALIMENTARY SYSTEM. 



171 



The parts destined to subdivide the food, the teeth, have been 
already described.* The adaptation of the sectorial teeth for the 
division of flesh is manifest and admirable. The canines are not 
used for dividing the food. They are 
weapons for seizing and destroying 
prey, or for combat. The incisors are of 
little functional utility, but they help 
to scrape off flesh and sinews from the 
surfaces of bones. The upper true 
molars are so small as to be of little 
service, but their shape and position 
adapt them for crushing any suitably 
sized object (such as a small piece of 
bone) which may have been taken into 
the mouth. 

§ 9. The tongue fills up the cavity 
of the mouth between the horizontal 
rami of the mandible. It is a mus- 
cular mass, coated with mucous mem- 
brane, attached behind to the hyoid 
and below to the membrane of the floor 
of the mouth, but with a free apex. 
It is long and flat, with nearly parallel 
sides, tapering slightly in front and 
more so at its posterior attachment. 

Its fleshy mass is principally composed 
of transverse fibres which pass directly 
right and left from a central, vertical 
membranous septum. This mass of trans- 
verse fibres is traversed by ascending 
fibres of the genio-hyoglossus muscle, 
and is coated externally by longitudinal 
fibres which form its cortical muscular 
layer. Above and below, these fibres 
belong to two muscles ; one, called 
the lingualis superficialis superior, pro- 
ceeds forwards from the basi-hyal, and 

the other, called the lingualis superficialis inferior, passes thence on 
each side of the ascending fibres above mentioned. The lateral 
longitudinal fibres come from the stylo -glossus and hyo-glossus. 
This mass of muscular fibres enables the tongue to move freely in 
all directions and to modify its own shape. 

Imbedded in the areolar tissue of the septum and near the lower 
surface of the tongue is a spindle-shaped body (formed of fibrous 
tissue, fat and muscular fibre), connected anteriorly with the 
mucous membrane of the tongue, and tapering off behind till it is 
lost in the tissue of the septum. This body is the lytta or "worm." 




Fig. 87 



Dorsum of the Tongue 
of the Cat. 

a. Arytenoid cartilage. 

cv. Circumvallate papilla}. 

e. Epiglottis. 

/. Fungiiorm papilse. 

p. Posteri r pilar of fauces. 

s. Co; ical pap.lla. 

t. Tonsil. 

v. Vocal cord. 



* See ante, p. 27. 



172 THE CAT. lchap. vi. 

Its function is unknown, but it is supposed to help the tongue in its 
lapping action. 

The mucous membrane, which invests the tongue, forms a fold 
beneath it and in front (attaching it to the lower jaw) termed the 
frcenum lingua, and thence it is continued onwards (over the muscles 
forming the soft floor of the mouth) till it reaches the gums. A 
minute process — the salivary papilla — projects forwards on each 
side of the fraenum. 

The upper surface of the tongue is flat, with a depressed area 
behind, which is bounded posteriorly by the epiglottis— or cartilage 
guarding the entrance to the windpipe. 

The surface of the tongue is smooth beneath, but above it is beset 
with papillae of four kinds: — 

/ 1.) The first are the circumvallate papilla, each of which consists 
of a flattened prominence (shaped like a truncated, inverted 
cone), with a sort of trench round it. A few of these are dis- 
posed in two rows converging posteriorly like a widely open 
letter V (Fig. 87, cv). 
(2.) The fungiform papilla are much smaller and more numerous 
than the circumvallate ones. Each is somewhat swollen and 
rounded at its tip, while it is smaller at its point of attach- 
ment. These papillae (/) are found especially at the sides of 
the anterior part of the tongue. 
(3.) The conical papilla are very numerous and closely set over 
the dorsum of the tongue, with their apices directed back- 
wards. They are small and simple near the edges and tip of 
the tongue, but over the greater part of the dorsal surface they 
are much larger and horny in consistency — like so many 
minute claws — especially towards the middle line. It is the 
presence of these horny papillae which makes the cat's tongue 
so rough and rasp-like. 
(4.) The flattened papilla are a group of very large, soft, flattened 
and pointed papillae, placed behind the circumvallate papillae 
on the dorsum of the root of the tongue. 
§ 10. Besides the secretion of the small mucous glands, the 
cavity of the mouth is moistened by the product of various kinds of 

SALIVARY GLANDS. 

The first of these, the parotid, is a branching, or racemose,* gland, 
consisting of many lobes held together by their excretory tubules, 
blood-vessels, and areolar tissue, and lined throughout with epithelium. 
It forms a crescentic mass, with its concavity applied to the under 
and anterior aspect of the cartilage at the root of the external ear, its 
lower border being prolonged downwards and forwards (Fig. 88, p). 
Its duct (called Steno's or Stenson's) runs forwards across the mas- 
seter muscle, and perforating the buccinator, opens inside the cheek 
opposite the sectorial teeth. Two small separate accessory portions 

* For a description of the different varieties of glands, see § 8, in the 
chapter on the Organs of Respiration and Secretion. 



chap, vl] THE CAT'S ALIMENTARY SYSTEM 



173 



lie opposite each other, one at the front margin of the parotid and 
the other at its hinder margin. Another supplementary gland (/), 
of an elongated oval shape, lies beside Steno's duct and opens into its 
cavity. It may be distinguished as the facial gland. 

The submaxillary gland (sm) is rather smaller than the parotid 
and more rounded. It lies behind the angle of the mandible, and 
is in contact above with the downward prolongation of the parotid 




JV 



Fig. 88.— View of Salivaky Glands and parts adjacent 

5. (At angle of mouth) buccal glands 
b. (Near ear) anterior or accessory parotid. 

6. (At beginning of throat) tin two accessory 

sub-maxillary glands with the facial vein 

passing b itween them. 
d. Duct of parotid gland (Steno's duct). 
/. Facial gland. 



jv jv. External jugular vein and (more anteriorly) 
facial vein. 

I. Hinder accessory parotid. 

n. Facial nerve. 

sm. Sub-maxillary gland. 

The duct of this gland is shown running for- 
wards above and nearly parallel with the 
vein jv, a bran h from which crosses over it. 



before mentioned. Its duct (called Wharton's duct) runs forwards 
beneath the facial vein and opens on the minute salivary papilla 
before described as being situated beside the fraenum of the tongue. 

There are two accessory submaxillary glands which lie side by side 
(separated by the facial vein (Fig. 88, jv) immediately adjacent to 
the lower and anterior end of the principal submaxillary gland. 

Another gland, called zygomatic, is of rather large size and pyra- 
midal shape. It lies beneath the globe of the eye on the orbital 
plate of the maxilla and inside the anterior end of the zygoma. 
It opens in the mouth behind the upper true molar. 



174 THE CAT. [chap. vi. 

The buccal glands are small glandular aggregations, each aggrega- 
tion opening by various minute orifices into the mucous membrane 
of the mouth. 

The secretion of all these glands constitutes the saliva, which is 
a clear, alkaline fluid, consisting mainly of water, but containing 
nucleated corpuscles, a peculiar albuminoid substance called salivin, 
or ptyalin, and a minute quantity of sulphocyanide of potassium. 

This secretion is poured out as it is formed, and its flow is accele- 
rated by the contraction of the cheeks and tongue. The secretion 
is stimulated by the presence of food in the mouth, and even by the 
sight of it. 

The action of this fluid on the food is, first, to soften it and dis- 
solve what is soluble, including all its crystalloids. It has no action 
on the albuminoid or gelatinoid substances, nor on the fats ; but it 
tends to convert starch (at the ordinary temperature of the inside of 
the mouth) into grape-sugar, thus changing a colloid into a crystal- 
loid, and so rendering the starch soluble and capable of undergoing 
absorption and assimilation. This action, however, is slow and 
feeble in the cat. It is the ptyalin which has this power, which it 
seems to exercise simply by the stimulating action of its presence and 
contact ; for if it is precipitated by alcohol, filtered, and then re- 
dissolved, it will quickly transform as much as 2,000 times its 
weight of starch into sugar. 

The food having been sufficiently bitten, it is thrust backwards by 
the tongue through the isthmus faucium. While it passes, the velum 
palati is raised, and so guards the posterior nares from the intrusion 
of the food, and the backward motion of the tongue depressing the epi- 
glottis, while the food passes over it, guards the entrance of the 
windpipe against the entrance into it of any alimentary matter. 

§ 11. Immediately behind the isthmus faucium is a conical cavity, 
wider towards its upper part, and more contracted below. This is 
the pharynx. It rises up behind the mouth and posterior nares to 
the base of the skull, and forms the summit of that canal which 
leads down from the mouth to the stomach. It consists of the 
pharyngeal muscles already described, with a lining of fascia and 
mucous membrane, together with vessels, nerves, and areolar tissue. 
It is attached above to the basi-sphenoid and petrosals, and to the 
basi-occipital by a fibrous membrane, which passes down between 
the recti antici muscles. It is loosely connected behind with the 
fascia, investing the pre-vertebral cervical muscles, and laterally 
with the muscles attached to the hyoidean anterior cornu. In 
front, it is connected with the pterygoids, the hyoid apparatus, and 
the larynx. 

There are seven openings into the pharynx. These are : the two 
posterior nostrils ; and external to these, the two Eustachian tubes ; 
in front, the mouth ; and below it, the larynx ; while inferiorly, the 
pharynx opens into (being continuous with) the oesophagus. Its 
mucous membrane is beset throughout with simple glands, while 
racemose glands are numerous in its upper part. 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 175 

Its epithelium is squamous, except on the hinder surface of the 
velum palati, and in the upper (or nasal) region of the pharynx, where 
we meet with ciliated epithelium. This very remarkable tissue 
consists of epithelial particles — nucleated cells — generally columnar 
in form, each having, freely projecting from its surface, from six to 
thirty thread-like processes, each from T oVo to 2 fl ' of an inch 
-in length (Fig. 11), like miniature human eye-lashes — whence 
their name. 

These minute processes have the wonderful property of performing 
constantly during life, and (in a warm atmosphere) for as much as 
forty-eight hours after death, repeated lashing movements ; each 
cilium bending itself with great rapidity, and then becoming more 
slowly straightened. All the adjacent cilia move in the same 
direction, thus producing a wave-like motion similar to that of a 
field of corn under a strong wind. 

The result of these multitudinous and constantly-repeated minute 
motions — each repeated about ten times in a second — is to propel 
small particles along the ciliated surface of the body. 

If a ciliated cell be detached, so as to float freely in some suitable 
fluid, then the effect of this action of its cilia is to move about the 
cell itself as by a sort of locomotion. Water checks the action of 
cilia, but blood will preserve it even for two or three days ; such 
action still continuing on slips of membrane detached from the 
body. !No muscular tissue and no nerve has been detected in the 
ciliated cells, nor are the actions of the cilia amenable to nervous or 
moderate electrical influence. They persist in the membrane which 
bears them when this is detached. The cause of their motion is 
as yet utterly inexplicable, an ultimate mystery like that of the 
contractile power of muscular tissue. 

The function of the pharynx is to direct the food which has 
just been pushed, through the isthmus faucium, downwards towards 
the stomach by means of successive contractions of its fibres from 
above downwards. It becomes more powerfully grasped as it 
approaches the oesophagus. This active prehension of aliment 
equally takes place when that aliment is fluid, none being allowed 
simply to fall down towards the stomach while the walls of the 
alimentary tract remain passive. 

§ 12. The gullet, or oesophagus, is a narrow, cylindrical tube, 
beginning at the bottom of the pharynx and extending downwards 
through the diaphragm, to terminate (immediately it has passed 
through that partition) in the stomach. It extends along above the 
trachea and heart, and beneath the vertebral column and longus colli 
muscle, being connected with those parts by lax areolar tissues. 

It is, of course, lined with mucous membrane, the surface of 
which is covered with squamous epithelium. 

The mucous membrane of the upper part of the oesophagus is 
folded (when the passage is not distended) in a number of vertical 
folds. 

The lower end of the oesophagus, for a short distance before 



176 



THE CAT 



[CHAP. VI. 



entering the stomach, has its mucous membrane elevated into 
transverse folds, which may be called " quasi valvulae conniventes. ,, 
Outside the mucous membrane is a layer of areolar tissue, and 

outside that is a thick muscular 
coat of two layers — the fibres of 
each being spirally directed, but 
.those of the inner layer being 
the more horizontal, and those 
of the outer layer the more 
longitudinal. Those of the outer 
layer are very thin, and wanting 
every here and there. There is 
much striated fibre at the upper 
part of the tube. 

§ 13. The ABDOMINAL CAVITY 

is bounded above by the ver- 
tebral column and muscles, la- 
terally by the abdominal muscles, 
in front by the diaphragm, and 
behind by the muscular and mem- 
branous partition, which closes 
posteriorly the cavity of the 
pelvis. 

On the middle of the outer 
wall of the abdomen there is in 
front a slight irregularity of sur- 
face, which is the " navel " or 
umbilicus. 

When the abdomen is opened 
by a median antero - posterior 
section through its ventral wall, 
and by the reflection of the 
walls bordering the cut, the fol- 
lowing organs come into view. 

Immediately behind the dia- 
phragm on the right side is seen 
the liver (I), with the gall-bladder 
protruding from amongst it (gb). 
In the middle line, partly beneath 
the liver, is the stomach (s), to 
the extreme right of which is 
the spleen (sp). From the 
stomach a flap of membrane, 
loaded with more or less fat, 
and called the great omentum (o), 
an apron, and conceals the more 
this is turned up or removed, a 
capacious transverse sacculated viscus may be seen to proceed trans- 
versely behind (below) the stomach ; this is the great intestine, behind 




Fig. 89 — View of the Cat's Viscera, in 
situ, the Body being opened on its ventral 

ASPECT. 



b. Urinary bladder. 


o. Omentum 


gb. Gall bladder. 


sp. Spleen. 


1. Lung. 


t. Trachea. 


li. Liver. 


s. Stomach. 


r. Bectum. 





extends towards the pelvis, like 
deeply situated viscera. When 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM, 



177 



which are the multitudinous folds of a narrower tube — the small 
intestine — while superficially, at the posterior end of the abdominal 
cavity, the bladder (b) may be seen. 




Fig. 90.— The Cat's Stomach and Pancreas. 



A. Left aspect of stomach. 



c. Cardiac portion. 
Id. Bile du t. 

d. Duodenum. 

gc. Great r curvatur3 



Ic. Les?er curvature 
cs. GEsophagu-i. 
p. Pylo.us. 
pu P ncr as. 




B. Pancreas. 



The pyloric part of the stomach is cut open to 

show the pyloric valve. 
d. Duodenum. 



p. Pylorus 

dec. Ductus communis choledochus. 

p d. Pancreatic duct. 



§ 14. The stomach is a dilatation of that part of the alimentary 
tube which lies immediately behind the diaphragm, rather to the 



178 



THE CAT. 



[CHAP. VI 



left. It is somewhat pear-shaped, but sharply bent upon itself. Its 
left and much larger end (c), is called the cardiac end, or cardia 
(because it is the nearer to the heart), and it is towards this end 



B 




Fig. 91. — Vertical Transverse 
Section of the Coats of a Pig's 
Stomach, magnified 30 diameters. 

a. Gastric glands. 

6. Deeper layer of mucous membrane. 

c. Sub-mucous or areolar coat. 

d. Circular muscular layer. 

e. Longitudinal muscular layer. 
/. Serous coat. 




92.— Gastric Glands from the Dog's Stomach, 
highly magnified. 

A. Portions of a s'mple tubular " Peptic" gland. 

1. Neck of the gland. 

2. Fundus. 

3. Transverse section. 
p. Peptic cells. 

h. Central ce Is. 

c. Ends of columnar cells. 

B. A gland of more complex shape. 

m. Mouth. 

n. Neck. 

tr. A deep portion cut transversely. 



that the oesophagus (ce) opens into the stomach. Its opposite end is 
called the pylorus (p), and is directly continuous with the intestine, 
the aperture by which the stomach opens into the latter being called 
the pyloric orifice. 

Its deeply concave surface between the oesophagus and pylorus is 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 



179 



etc 



called its " lesser curvature (Ic). The opposite very convex side 
is called its greater curvature (gc). 

Its structure is essentially similar to that of the oesophagus. Its 
muscular coat, formed of organic fibres, consists of an outer radiating 
layer, directly continuous with the more longitudinal layer of the 
oesophagus. Within this is a 
layer of circular fibres which 
extends over the whole sto- 
mach, and is especially thick 
at the pylorus, where it forms 
a sphincter which, project- 
ing inwards, constitutes (with 
areolar tissue arid its mucous 
lining) what is called the ''py- 
loric valve " (Fig. 90, B, pv). 

Within the second muscular 
layer is yet a third set of 
obliquely disposed fibres. 

Immediately within the 
muscular stratum is a layer 
of submucous areolar tissue, 
which directly supports the 
mucous lining of the stomach. 
This lining is soft, thick, and 
smooth, and is so loosely 
connected by the areolar layer 
with the muscular coat, that 
it is thrown into numerous, 
regular, undulating effaceable 
folds when the stomach is 
not distended. The inner 
surface of the stomach is 
everywhere beset with small 
pits, which are the orifices 
of minute close- set gastric and 
peptic glands, which may be simple tubes or more or less branching. 

At the lower end of the oesophagus the squamous epithelium ceases 
and gives place to what is mostly of the columnar kind. 

The function of the stomach is partly mechanical, since by their 
contractions, its many muscular fibres rotate its contents, and so 
expose all parts in turn to the action of its secreting walls while they 
drive it towards the pylorus, and send through that aperture such 
portions of it as are sufficiently dissolved or soft. Regurgitation of 
food into the oesophagus is prevented by the contraction of the 
circular fibres which surround its entrance into the stomach. The 
main action of the stomach is digestive through the gastric juice. 
This consists of water, with some two per cent, of saline matters, 
a minute quantity of free hydrochloric acid and a little more 
than three per cent, of pepsin, a neutral, albuminoid substance. 

N 2 




Fig. 93. — Thi Intestinal Tube of the Cat, seen 

VENTRALLY, WITH TS FOLDS SOMEWHAT SEPARATED. 



a Anus. 

ac. Ascending colon. 

ce. CE-ophagus. 

c. Cardia. 
cm Gee u m. 

d. Duodenum. 

dc. Descending colon. 



Ic. Lesser curvature. 

p. Pylorus. 

r. Rectum. 

si. Small intestine. 

st. Stomach. 

tc. Transverse colon. 

x. Greater curvature. 



180 



THE CAT. 



[CHAP. VI. 



The gastric juice is colourless, or pale yellow, and strongly acid. 
Its action on albuminoids and gelatinoids is to change them into an 
extremely soluble form called peptone. It has no direct action on 
the amylaceous foods (rather arresting the process of converting 
starch into sugar) nor on the oleaginous matters. The contents of 
the stomach when all the action of that organ has been brought to 
bear upon it, is called chyme. 

A certain amount of matter is directly absorbed by the vessels of 
the walls of the stomach, but this function is far more perfectly per- 
formed by the small intestine. 

§ 15. The part of the alimentary canal which succeeds the 
stomach is the intestine, which is so convoluted as to be about five 
times the length of the whole body in the domestic cat, though it is 
said to be considerably shorter in the wild cat. 

The part of this tube which comes first, is called the small 





im 



v e 

Fig. 94.— Intestinal Villi. 



A. Section through the small intest ; ne, showing 

the numerous villi, with iheir orifices 
directed towards the central cavity. 

B. A single villus, greatly magnified. 

C. Section of the wall of the intestine, and of a 

few villi less magnified than Fig. B. 



e. Epithelium. 
em. External muscular layer. 
im. Internal muscular layer. 
p. Peritoneal investment. 
v. Vessels within a villus. 



intestine, and is very much longer, though smaller in calibre, than 
the succeeding portion. It is also by far the most convoluted part 
of the alimentary tube. It is cylindrical and about three feet eight 
inches in length, and of nearly the same diameter throughout. It 
is spoken of as consisting of three parts : the duodenum, jejunum, 
and ileum. 

The duodenum comes next to the stomach, and describes a rather 
wide curve, which embraces the pancreas and receives its duct and also 
that from the liver. It lies on the right side of the abdomen. The 
jejunum is its continuation thence to the right side, and to it succeeds 
the mass of the small intestine which is formed by the ileum, and 
lies at the posterior and middle part of the abdominal cavity. 



chap, vi.] TEE CAT'S ALIMENTARY SYSTEM. 181 

The inner surface of the small intestine does not form transverse 
folds, but is clothed with a velvet-like lining made up of a multitude 
of very tine, short, closely-set filaments or villi. These filaments 
are prolongations of the corium, invested with columnar epithelium, 
and contain Mood- vessels, and a central vessel which is not a blood- 
vessel, but is called a lacteal. The lacteals open proximally into 
vessels belonging to the same category as they themselves do, and 
which lie in the submucous areolar tissue. 

The lining of the small intestine is also beset wdth glands. The 
most noticeable of these are aggregations of glands, which aggre- 
gations go by the name of Pcyer's patches. There are in the small 
intestine some six or seven of such patches, more or less narrow and 
elongated, especially the one at the posterior end of the ileum, which 
is clothed with villi like other parts of the intestine. Each patch is 
made up of a number of glands, or vesicles, smaller than a pin's 
head, composed of connective tissue, and containing a whitish fluid 
with nucleated cells. 

Besides these structures, small glands of Lieberkuhn (like the 
simple glands of the stomach) abound between the villi, and there 
are other glands called Brunei's glands, w T hich are branching 
structures, most numerous in the duodenum. 

The small intestine is composed (1) of an outer or serous coat ; 
(2) of two muscular layers ; (3) of an areolar or submucous coat ; and 
(4) of the mucous lining. The serous coat is the peritoneal invest- 
ment of the intestine, which is continuous with the two layers of the 
mesentery by which it is suspended. It is wanting in part of the 
duodenum. Of the muscular coats, the thinner external layer is 
formed of longitudinal fibres, while in the thicker, inner layer they 
are arranged circularly at right angles to the long axis of the tube. 
The submucous coat is a layer of loose substance of areolar tissue 
with fine elastic fibres, amdist which the blood-vessels ramify, and 
subdivide before entering the innermost or mucous coat. 

The function of the small intestine is, like that of the stomach, 
partly mechanical and partly solvent. The successive contractions, 
from before backwards, of its muscular walls tend to drive the 
contents towards the large intestine. Such motion is, like the 
similar movements of the fibres of the stomach, called peristaltic 
action. This form of movement is also spoken of as the vermicular 
motion of the intestine, and if the animal be suddenly killed, and its 
abdomen opened, the peristaltic action will be seen still taking place, 
and giving to the intestine an appearance as of so many crawling 
worms — whence the term " vermicular." 

The process of digestion is further aided, as we shall hereafter see, 
by the products of the pancreas and liver, and also somewhat by 
the secretions of the crypts of Lieberkuhn's and of Bruner's glands. 
The former secrete the intestinal juice proper, which is colourless, 
and seems to be a form of mucus. 

The chyme of the stomach, having been modified by the action of 
all these secretions, changes into what is called chyle, the secretion 



182 



THE CAT. 



("CHAP, VI. 



of the pancreas, and that of the liver, converting more of what 
remains of starch into sugar, dissolving more of what nitrogenous 
food has not been dissolved already, and making (by minute division 
and mixture) the oleaginous matters into an emulsion. 

But one great office of the small intestine is the absorption of 
nutriment. This is already begun through the walls of the vessels 
of the stomach, but the villi of the intestine carry it on much more 
effectively. The most easily dissolved or transmissible fluid passes 
into the blood through the walls of the blood-vessels of the 
villi, while fatty and albuminoid matters find their way into the 
lacteals. 

§ 16. At the end of the small intestine, at its junction with the 
large, is a blind diverticulum or cul-de-sac, called the caecum. 

The large intestine is rather more than a quarter of the length 
of the small intestine (it is about a foot long), but it is considerably 




Fig. 95.— The Caecum. 



A Seen externally. 

B. Cut open. 

cce. Caecum towards its apex. 



g. Mesenteric glands. 

i. Ileum. 

v. Ilio-csecal valve. 



wider and tolerably uniform in width, tapering somewhat to its 
hinder end. Instead of being extremely convoluted, it forms but a 
single sweep forwards, transversely, and backwards. Its exterior 
exhibits a few slightly-indicated transverse depressions. It begins 
on the right side of the abdominal cavity, and passes forwards as 
what is called the ascending colon ; it passes across to the left, on the 
posterior side of the stomach, as the transverse colon, and then turns 
backwards as the descending colon, ending in the terminal portion 
of the intestine called the rectum. 
The ciECUM may be said to be that part of the large intestine 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 183 

which projects blindly (whence its name) beyond the point at which, 
the small intestine opens into the ascending colon. It is a short, 
wide, simple, rather conical part, narrowing rapidly to its apex, but 
having its terminal portion more or less sharply bent towards the 
ileum, and separated off from the rest by a slight constriction — so 
that it forms a sort of appendix to the rest of the caecum. This 
terminal portion is thick-walled and glandular, being lined by a sort 
of Peyer's patch. The entrance from the ileum into the caecum is 
by a circular constriction (with its margin prolonged somewhat into 
the caecum) called the ileo-ccecal valve. 

There are many glands in the rather thick walls of the caecum, 
especially towards its apex. 

On each side of the hinder end of the intestine are two large 
secreting pouches, or anal glands, each of which would contain a 
very large pea within its cavity. They are both embraced and 
invested by the external sphincter muscle, and are lined by glandular 
mucous membrane. Each gland opens externally just within the 
margin of the anus by a short duct, the inner end of which projects 
inwards into the cavity of the gland, of which it is the excretory 
channel. 

The structure of the large intestine essentially resembles that of 
the small. It exhibits irregular internal folds in the descending 
colon, and in the rectum ; and there are numerous follicles scattered 
throughout its whole extent, but its surface is not raised into 
processes or villi. There is thus a great contrast between its 
interior and the villous internal surface of the small intestine. 

The function of the large intestine is in great part mechanical. 
By its contractions its contents are driven onwards to the rectum, 
whence they are expelled by the contraction of the rectal walls and 
the simultaneous relaxation of the sphincter ani — the expulsive 
action being aided by the contraction of the muscular walls of the 
abdomen, and the backward pressure of the diaphragm. The power 
of absorption of this part of the alimentary tube is much less than 
that of the small intestine, as is evidenced by the absence of villi. 
Nevertheless it does possess a certain power of absorption, and it 
not improbably also serves to extract from the blood, and cast forth 
into the intestinal cavity, some substances, the removal of which is 
beneficial to the organism. 

§ 17. The pancreas (Fig. 90, B) is a large, racemose gland, 
composed of, and entirely invested by, peritoneum. It consists of 
lobes and lobules of different sizes, connected together by areolar tissue, 
vessels and ducts, being in fact like the parotid gland, but somewhat 
looser in structure. In shape it is elongated and narrow, and is 
indistinctly divisible into two parts. One portion of it, the body, 
lies posterior to and above the posterior border of the stomach 
(enclosed between the layers of the posterior fold of the great 
omentum) on the right ; the other and larger part, the head, passes 
backwards along the concave margin of the duodenum. It has two 
ducts ; one of these joins the common bile-duct (from the liver) 



184 



THE CAT. 



[CHAP. VI. 



before entering the intestine, and the other enters the duodenum, 
separately, an inch or more further backwards.* 

The function of the pancreas is to secrete a special fluid, the 
pancreatic juice, which has in part the nature of saliva, inasmuch as 
it tends to convert starch into grape sugar. Unlike saliva, however, 
it has a powerful effect on albuminoid and gelatinoid matters, con- 




Fig. 96. — Cat's Liver, viewed from behind. 



R. Right moiety of the liver. 
L. Its left moiety. 

c. Caudate lobe. 
cf. Cystic notch. 

d. Duodenum. 
gb. Gall bladder. 

Ic. Left central lobe. 

II. Left 1 iteral lobe. 

If. Left lateral fissure. 

re. Smaller portion of righ central lobe. 



rl 2 . Larger portion of right central lobe. 

rl } . Right lateral lobe. 

rf. Right lateral fissure. 

hv. Portal vein. 

s. Spigelian lobe. 

u. Umbilical fissure. 

bd. Ductus communis choledochus. 

o. Its opening into the duodenum. 

p. Pylorus. 



verting them, as the gastric juice does, into peptones. Besides 
these actions it also emulsifies fats. 

§ 18. The liver is the largest gland in the body, and lies mainly 
to the right, immediately behind the diaphragm, between it and the 
stomach, and protected by the cartilages of the ribs. Certain large 



* In some cases a duct has been seen 
to lead, from the point of junction of the 
ducts above mentioned, to a small sac, 



serving to retain some of the secretion of 
the pancreas as the gall-bladder retains 
that of the liver. 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 185 

blood-vessels (the aorta and vena cava) are interposed -between it 
and the bodies of the vertebra. 

It is a solid organ, thick dorsally, and thinning out below ; of a 
reddish-brown colour, smooth and convex towards the diaphragm, 
but concave and uneven on its opposite surface. It is divisible into 
certain parts, or lobes, which are defined and marked off, partly by 
grooves and notches in its substance, partly by ligaments and blood- 
vessels connected with it. 

The liver is divided into two unequal lateral halves by a mem- 
branous ligament (the broad or falciform ligament), which passes to 
it from the adjacent surface of the diaphragm, and which consists of 
two folds of peritoneum, as will be hereafter explained. This 
ligament is attached to the liver in a line running from its dorsal 
margin to its ventral border ; and the part on the right side of it is 
the larger. 

When the posterior surface of the liver is in view, a deep notch (u) 
and groove may be observed opposite to, and corresponding with, 
the attachment of the broad ligament. This groove is called the 
longitudinal fissure, and it lodges a fibrous cord called the round 
ligament. The anterior part of this cord (which passes upwards to 
the liver from the navel) is the remnant of a structure temporarily 
developed in the very young condition — the umbilical vein — while 
the posterior part of the cord (which joins the vena cava) is the 
remnant of another primitive vessel — the ductus venosus. 

On this account the ventral part of the groove is called the 
umbilical fissure (u), while its posterior part is named the fissure of 
the ductus venosus. This fissure then divides the liver into two 
unequal lobes on its hinder surface, and each of these is again 
subdivided by other fissures. Thus a small, prominent, undivided, 
somewhat pyramidal lobe (called Spigelian) is placed almost medially 
at the dorsal border of the liver (s), its apex extending outwards 
on the hinder surface of the left lateral lobe (//). It is bounded on 
the right by a short deep groove called the fissure of the vena cava, 
because it is traversed by that vessel. The Spigelian lobe is bounded 
ventrally by the transverse or portal fissure which runs, almost at 
right angles, into the longitudinal fissure. It is into this transverse 
fissure that the portal vein, the hepatic artery and the great nerves 
enter, and it is from it that the main bile ducts proceed to convey 
away the biliary secretions. 

The portal fissure runs to the right, beyond the limits of the 
Spigelian lobe. That part of the substance of the liver which is 
situate on the dorsal side of this outer part of the portal fissure, is 
called the caudate lobe (c). It is a moderate-sized, ridge-like lobe, 
which proceeds from the base of the Spigelian lobe to and along the 
hinder surface of the right lateral lobe (rl 1 ), and is more or less 
limited behind by the vena cava. 

The right lateral lobe is small and separated from a much larger 
lobe, the right central (rl 2 ) — which lies next it but nearer the middle 
line — by a deep fissure called the right lateral fissure {if). The 



186 



TEE CAT. 



[CHAP. VI. 



posterior surface of the right central lobe is marked by a depression in 
which lies a pear-shaped bag — completely invested by peritoneum — 
called the gall-bladder, which has its blind end (or fundus) 
directed downwards near (gb), the ventral margin of the liver. The 
notch at which its fundus is situated, and the depression in which 
the bladder lies, is called the cystic fissure (<?/). The fundus of 
the gall-bladder is occasionally buried in the liver's substance, and 
appears, through a cleft, in its convex surface. The part of the 
right central lobe which lies to the left of the gall-bladder (re) is 
itself bounded on the left by the umbilical fissure already described. 




Fig. 97.— Section of a portion of the Liver (of the Pig), passing longitudinally 

THROUGH A CONSIDERABLE HEPATIC VEIN, ENLARGED ABOUT FIVE DIAMETERS. 



H. Hepatic venous trunk, against which the 

sides of the lobules are applied. 
h, h, h. Three sub-lobular hepatic veins, on 

which the bases of the lobules rest, and 

through the coat < of which they are seen as 

polygonal fissures. 



i. Mouth of the intra-lobular veins, opening into 

the sub-lobular veins. 
i'. Intra-lobular veins, shown passing up the 

centre of some divided lobules, 
c, c. Walls of the hepatic venous canal, with the 

polygonal bases of the lobules. 



Beyond it lies a very small lobe, the left central lobe, which is 
separated from a very large lobe — the left lateral lobe (11) — by a 
deep fissure called the left lateral fissure (If). 

The bile, or hepatic, ducts issue from the lobes of the liver and 
the portal fissure, and join the duct which comes- from the gall- 
bladder. The latter duct is called the cystic duct, and the common 
duct formed by its union with the hepatic ducts, is termed the 
ductus communis choledochus (bd). This opens into the duodenum at 
about f n inch and a half from the pylorus — after being joined by 
one of the pancreatic ducts. 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 



187 



d a 



The cystic duct is convoluted, making about four turns, held 
together by areolar tissue. 

The several hepatic ducts correspond with the different lobes 
of the liver, and are formed by the union of small ducts arising 
from the several liver (or hepatic) lobes. The ductus communis 
choledochus sensibly enlarges 
as it traverses the coats of the 
duodenum. 

The MINUTE STRUCTURE of 

the liver consists of a com- 
plex arrangement of microscopic 
blood-vessels and cells, con- 
nected by areolar tissue, as 
follows : — 

When the substance of the 
liver is cut across, its solid sub- 
stance presents a mottled ap- 
pearance, and careful inspection 
shows that it is made up of a 
number of polygonal masses, 
which are called lobules. These 
lobules are seen to be arranged 
around a number of canals pro- 
ceeding in two directions. One 
set of canals diverge from the 
portal fissure, and these are 
called portal canals. The other 
set of canals converge to the 
inferior vena cava, and these 
are called hepatic veins. Now, 
as will be hereafter seen, the 
blood is of two kinds, arterial 
and venous, and is respectively 
conveyed (except as regards the 
lungs,) by vessels called arteries 
and veins, accordingly as they 
carry the one or the other kind 

of blood. JSTo less than three sets of vessels ramify in the substance of 
the liver, two sets conveying blood into, and one set (the hepatic veins) 
convening blood out of it. Of the two sets of vessels conveying blood 
into it, one is arterial, the hepatic artery; the other is venous, the portal 
vein. These ramify in the portal canals along with branches of the 
hepatic ducts, the whole three sets of ramifications being surrounded 
and supported by areolar tissue, which is continuous with a fibrous 
membrane which invests the external surface of the liver generally. 
The several branches of the portal vein are much larger than the 
accompanying hepatic ducts, and these are somewhat larger than 
the arteries. The arteries convey nutriment to the framework 
of the liver, its branches ending in the walls of the ducts, blood- 




Fig. 98. — Longitudinal Section of.a Portal 
Canal, containing a Portal Vein, Hepatic 
Artery, and Hepatic Duct, from the Pig. 
Enlarged about five diameters. 

P. Branch of vena portae, situated in a portal 
canal, formed anio. gst the hepatic lobules 
of the liver. 

pp. Larger branches of the portal vein, giving 
off smaller ones (i i), named inter-lobular 
veins ; there are also seen within the larg i 
portal v. in numeious orifices of i ter- 
lobular veins arising directly from it. 

a. Hepatic artery. 

d. Biliaiyduct. 

At c c, the venous wall has b en par.ially 
removed. 



188 THE CAT. [chap, yj. 

vessels, and in the areolar tissue. The portal veins end hy minute 
vessels, which surround and penetrate the lobules of the liver 
(whence they are called interlobular veins), while the hepatic ducts 
end in most delicate canals, which pass amongst the hepatic, or 
liver, cells, which make up the substance of the lobules between 
its multitudinous vessels. 

The blood being thus conveyed to the circumference of each 
lobule, proceeds thence to its centre, where it collects in the com- 
mencements (ultimate twigs) of the hepatic vein which, from the 
fact that they thus take origin, are called intra-lobular veins. 

The liver cells (or hepatic cells) form the secreting substance of 
the liver, and are spheroidal or polygonal nucleated bodies of a 
yellowish colour, containing granules and fatty matter besides the 
nuclei. They vary from T ^ to t -^-q of an inch in diameter. 

The function of the liver consists in the secretion of bile, 
though the full meaning and effect of its activity is not by any 
means entirely understood. 

Bile is an alkaline, greenish-yellow, viscid, bitter fluid, containing 
from 8 to 16 per cent, of solid matter, consisting principally of a 
compound nitrogenous substance termed bilin. It also contains a 
non-nitrogenous substance called cholesterin, with certain salts and 
peculiar colouring matters (biliverdin and bilifulvin) containing iron. 
These colouring and other substances are formed by the cells of the 
liver, and do not pre-exist in the blood. 

Another substance which is found accumulated in the liver after 
death, does not escape by the hepatic ducts. This is glycogen or 
animal starch. 

The rapidity with which bile is secreted varies according to 
circumstances, increasing during the process of digestion. 

The bile does not all pass directly into the intestine, but part of 
it regurgitates along the cystic duct into the gall-bladder, where it 
may remain for a certain time, and where it becomes somewhat 
thickened. 

The action of the bile on the food is, in the first place, to neutra- 
lize the acid of the chyme, and secondly, to aid in emulsifying 
fatty matters. 

But in addition to its effect on food, the secretion, of bile is 
important as a mode of eliminating from the body substances, the 
removal of which is necessary to healthy life. The colouring 
matters of the bile are always entirely excreted, but other of its 
constituents appear to be decomposed in the large intestine, their 
nutritious matter being re- absorbed and their refuse driven on as 
excretin, stercorin and some other substances. 

Yet other functions are performed by the bile, namely, that of 
exciting, directly or indirectly, the action of the intestinal mucous 
membrane and also the peristaltic action. 

It is also said to have an anti-putrescent action on the food, 
putrefaction taking place in the alimentary canal in the absence 
of bile. 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 189 

§ 19. The peritoneum is the large closed sac, formed of very- 
delicate membrane, which both lines the abdominal cavity and coats 
its contents. It is one of a class of membranes called " serous," 
from the nature of the colourless fluid with which their surfaces 
are moistened, and which is more or less like the " serum " of the 
blood. Part of the membrane is applied to the inner surface of 
the walls of the abdominal cavity, and this is called its parietal 
portion, but it is every here and there reflected from the walls 
over the viscera contained within them, and such reflected parts 
are called its visceral or reflected portion. Thus the viscera nowhere 
enter into the real cavity of the peritoneal sac, while their move- 
ments can take place without friction because the moist inner 
surfaces of the peritoneum are everywhere juxtaposed, however 
complex and complete may be wrappings round which the viscera 
receive from the inflexions of this highly complex sac. 

The membrane is formed of connective tissue, which is lined by a 
layer of squamous epithelial cells. 

The layer of epithelium thus lining a serous cavity is called 
endothelium. The peritoneal serous membrane is attached to the 
parts to which it is applied by fibres of more or less loose areolar 
tissue. 

The form or arrangement of the peritoneum is exceedingly 
complex, owing to the contorted and unsymmetrical arrangement of 
the viscera which it invests, and which fill the abdominal cavity 
In development, as will be hereafter seen, the alimentary canal is 
primitively an exceedingly simple tube traversing the abdominal 
cavity from before backwards. The peritoneum lining the ventral 
surface of the abdomen is continued upwards along its sides, nearly 
to the middle line, whence each lateral layer is reflected ventrally, to 
embrace closely each side of the alimentary tube, and to meet the 
reflection of the lateral layer of the other side, upon the ventral 
surface of the alimentary tube. Thus this tube is enclosed and 
slung in a fold of membrane, and really lies (as before said) external 
to the peritoneal cavity; though the two reflected folds (between the 
alimentary tube and the back of the abdominal cavity) become so 
closely applied together as to seem to form but one membrane. 

As development proceeds, the alimentary tube becomes differen- 
tiated into regions of very different capacities ; while, at the same 
time, it becomes enormously elongated, contorted, and unsymmetri- 
cally disposed, and so the membrane which holds it enclosed and 
attaches it to the dorsal wall of the abdominal cavity, becomes 
necessarily drawn out and folded in a very complex manner ; and 
this complexity is increased by the fact that layers of the membrane 
which are primitively distinct grow together with contact, till they 
appear to be but one membrane. 

Folds of the peritoneum which retain the primitive condition 
and still suspend portions of the alimentary canal from the mid- 
dorsal region of the abdominal cavity, are termed mesenteries ; folds 
of peritoneum which pass from one viscus to another, are called 



190 THE CAT. [chap. vi. 

omenta ; and folds which pass from the abdominal wall to viscera 
which do not form parts of the alimentary tube itself, are spoken of 
as ligaments. 

The peritoneum forms a truly closed sac in the male, hut in the 
female it has two small openings, which indirectly communicate with 
the external surface of the body. These openings are the mouths 
of the " Fallopian tubes." 

Of the mesenteries, the mesentery par excellence is that which 
connects the small intestine with the dorsal abdominal wall, and 
conveys vessels to it. It contains numerous mesenteric glands (to 
be noticed hereafter in connexion with the lymphatic system) and 
vessels. Its vertebral border is very short, but its intestinal border 
is of course drawn out nearly to the length of the small intestine. 
Other folds attach the large intestine to the back of the abdominal 
wall, and are respectively called the meso-colon and meso-rectum. 

The omenta are three in number, and the first and largest 
of these, the great or g astro -colic omentum, is really a modified 
mesentery, being an enormous extension of that membrane which 
primitively connected the stomach with the body-wall, and which is 
produced and folded on itself so as to form' a great sac, constituting 
that apron-like fold which was before spoken of as covering the 
intestines when the abdominal cavity is laid open in front. 

Anteriorly, the great omentum is attached to the stomach along 
its greater curvature ; posteriorly, it is attached to the- dorsal 
surface of the abdominal wall. Thus, this great omental sac con- 
sists really of four layers. 

That it must do so is plain, since every mesentery consists of two 
layers (which hold between them the viscus they suspend), and, the 
great omentun being a pouch formed by the bulging out of a 
mesentery in a sac-like manner, each wall of the sac (being a part 
of a mesentery) must consist of two layers. 

The second, gastro-hepatic, or lesser omentum, passes backwards 
from the hinder surface of the liver to the pyloric part of the 
stomach, and the beginning of the duodenum. Its two folds extend 
from the two sides of the portal fissure, and have between them the 
portal vein and hepatic artery, as well as the gall- duct. 

The third, or gastro-splenic omentum, proceeds from the cardiac 
region of the stomach to the hilus of the spleen. There it divides, 
one layer passing all round the outer surface of the spleen, and 
returning to the other side of the hilus, whence the two layers pro- 
ceed side by side to the diaphragm; forming what might be called 
a mesentery of the spleen. Between these layers the blood-vessels 
proceed to the spleen and to the stomach, showing that the gastro- 
splenic omentum is the remains of the proximal part of what was 
originally the gastric mesentery. 

By the folding of the peritoneum upon itself with the development 
of the viscera, the edge of the gastro-hepatic omentum is brought 
so near the posterior abdominal wall that but a small space is left 
between. This space is called the foramen of Winslow, and the 



chap, vi.] THE CAT'S ALIMENTARY SYSTEM. 191 

inner surface of the great omental sac is continuous with its 
margins ; and thus, through it alone, is a communication established 
between the cavity of that sac and the general abdominal peritoneal 
cavity. 

The ligaments formed by folds of peritoneum, except those of the 
uterus (which will be noticed with the generative organs), are also 
three in number, all proceeding to the liver. 

The first of these, the falciform ligament of the liver, is a double 
layer of peritoneum proceeding backwards from the hinder surface 
of the diaphragm and the abdominal wall down to the navel, to the 
anterior surface of the liver, where its line of attachment, as we have 
seen, divides that viscus into its right and left halves. From that 
line of attachment the two layers of the ligament separate and pro- 
ceed right and left to invest the surface of the liver. 

In the posterior, ventral free margin of the ligament (between the 
ventral abdominal wall and the liver) is a fibrous cord called the 
round ligament, and which is the relic of a fetal structure. It 
extends from the navel to the longitudinal fissure on the hinder 
surface of the liver, as before described. The third ligament con- 
nects the dorsal border of the liver with the diaphragm. 

Thus, the general investing arrangement of the peritoneum 
lines the interior abdominal wall, and invests the viscera, as 
follows : — It invests the liver, except where reflected from it ; 
the hinder surface of the gall-bladder ; the stomach (except the 
narrow line of attachment at each curvature) ; the spleen, except at 
its hilus ; the ventral surface only of the pancreas and kidneys, and 
the anterior surface of the bladder. Almost all the small intestine, 
and more or less of the large intestine and rectum, are completely 
invested by peritoneum. Thus, these viscera are described as having 
a fourth or" serous coat in addition to the muscular, areolar, and. 
mucous coats already described. 



CHAPTER VII. 



THE CAT S ORGANS OF CIRCULATION. 

§ 1. The organs of circulation, or the circulating or vascular * 
system, comprises all that great system of tubes (of very various 
sizes) which have already been referred to, as arteries and veins, 
and all the various channels, or vessels, by which the nutritive fluid 
of the body — the blood — is conveyed to and from every part of the 
cat's frame. 

That it should be so conveyed is a manifest necessity of life, for 
since the process of nutrition takes place in the very innermost 
substance of the body (as has been already pointed out), there must 
be channels by which every part of the body may be supplied with 
its needed nutriment. Such nutriment is to be found in the blood, 
which has the power of repairing the waste of the tissues and sup- 
plying the materials for assimilation and growth, but which cannot 
obviously carry this power into effect except by moving from space 
to space throughout the body — without, that is, being propelled by 
"organs of circulation," and without exuding from the ultimate 
ramifications of such organs, to reach the very parenchyma itself. 

But we shall see in the next chapter that processes of gaseous 
interchange, " respiration," and of the elimination of waste and other 
products, "secretion," also really take place in the innermost paren- 
chyma, and not on the surfaces of the inner lining of the tubes of 
the various organs and internal cavities. Yet all that is so given 
out or exchanged must (if respiration and secretion are to be effected) 
find its way to such surfaces, and in order that it may be able so to 
do, we also require the aid of the circulating system. But the blood, 
in and by the very act of nourishing the various organs, must part 
with its nutritive material, and this, therefore, requires to be re- 
plenished if life is to be maintained. The needful gaseous matters 
are obtained by it in respiration ; but the other matters have to be 
gathered from materials prepared for it within the alimentary canal. 
These materials, we have already seen, in part pass directly into the 
blood-vessels which surround that canal, and in part into the vessels 

* A condition of vascularity (i.e., the I been attributed to certain tissues, such 
presence of blood-vessels) has already I e.g. as the dermis, intestinal villi, &c. 



chap, vil] THE CAT'S ORGANS OF CIRCULATION. 193 

called "lacteals," which are to be found in the intestinal villi. These 
lacteals we shall see open into tubes called " lymphatic vessels" or 
" lymphatics,'" and which vessels ultimately open and pour their 
contents into certain veins, after traversing — here and there in their 
course — certain bodies called lymphatic glands. The lymphatics do 
not contain " blood," but a colourless fluid called "lymph," consisting 
in part of the nutritious material absorbed from the walls of the ali- 
mentary canal, and partly of such of the colourless matter of the blood 
as has exuded from the vessels in order to effect nutrition, but 
has not been made use of. It is therefore taken up again by the 
lymphatics to be by them reconveyed to the blood-vessels. We 
have thus two nutritive fluids — " blood " and " lymph " — enclosed 
in two systems of vessels,, "blood-vessels " and '' lymphatics." 

The blood-vessels form a system of tubes completely closed, save 
at the apertures where the lymphatics open in them. In part, the 
vessels are of microscopic dimensions, but in one place the system is 
dilated into a large, complexly formed, rhythmically contractile 
organ — the heart. 

The heart may be considered as the central portion of the circu- 
lating system, all the other channels being subsidiary to it. These 
latter may be divided into three categories : (A) the vessels taking 
blood from the heart — which vessels are called arteries; (B) the 
vessels taking blood towards the heart — which are the veins; and 
(C) certain minute tubes which convey the blood to the tissues, and 
intervene between and connect the ends of the arteries and veins — 
the capillaries. 

It may be well before proceeding to examine in detail these 
various parts, and those other parts which compose the lymphatic 
system, to consider the two fluids which these two sets of organs 
respectively convey. 

§ 2. The blood is a thickish alkaline fluid, somew T hat heavier than 
water, which has a saltish taste and a faint odour, and is of a more 
or less scarlet or more or less purple red, according to circumstances. 
It consists mainly (more than 75 per cent.) of water, with a con- 
siderable quantity (12 to 14 per cent.) of an albuminoid substance 
termed haemoglobin, the rest consisting of albumen and other protein 
matters and salts. A nitrogenous substance called fibrin may be 
obtained from fresh-drawn blood by whipping it with slender rods — 
the fibrin then adhering to the rods in the form of a soft, whitish, 
stringy matter. Though apparently homogeneous to the naked eye, 
blood spontaneously separates (when drawn from the body and 
allow r ed to stand undisturbed) into different parts — one fluid, the 
other more or less solid. 

This process of solidification is called coagulation,* and it occurs 
thus : the fresh-drawn blood forms itself into a jelly-like mass, 



* Fibrin, as such, does not exist in 
the blood. It is supposed by some to be 
formed by the chemical union of two 



albuminous substances, which exist side 
by side in the blood while alive. 



194 THE CAT. Lchap. vii. 

but soon drops of clear fluid exude from it, and collect to form what 
is called the serum, while the solid mass left behind is the clot. 

Sometimes the clot is of a lighter colour above than below, show- 
ing that the clot itself consists of two elements, as is indeed the case. 
The clear part of it, is that substance which it has been said may be 
obtained by whipping, namely, " fibrin ; " while the red part, when 
examined by the microscope, is found to owe its colour to the presence 
of an immense multitude of minute coloured discoidal bodies called 
corpuscles* and which may be seen to float freely about in quite 
fresh blood, or in blood which (from the addition of salt or some 
other suitable matter, or from being kept at a low temperature) is 
prevented from coagulating. 

Thus fresh blood is found to consist of corpuscles floating in a 
fluid — the liquor sanguinis — which fluid yields both fibrin and serum. 
When coagulation takes place the fluid of the blood separates into 
two parts. One, the fibrin, solidifies, and, by entangling the cor- 
puscles amongst its filaments, forms the clot, while the remaining 
part of the liquor sanguinis escapes as the serum. 

The coloured, or red corpuscles are disc-like structures, only about 
the t'4-q-o of an inch in diameter, or even less. They are circular in 
outline, and each flattened side is concave and medianly depressed, 
so that each disc is thinnest from side to side in its middle, with a 
somewhat enlarged circumference. 

These corpuscles have no limiting membrane, though their ex- 
terior is somewhat denser than their interior, and they are soft and 
elastic. They exhibit no interior structure and no nucleus, but they 
consist of haemoglobin containing iron. Each is of a yellowish red 
colour, but by their excessive multitude they produce the deep red 
colour of the blood. In blood drawn from the body they tend to run 
together in strings, applying themselves face to face like piles of 
coins. 

Besides the red corpuscles, the blood also contains a variable 
. quantity of white corpuscles. These are much ] ess numerous than 
are the red, there being only some two or three white to a thousand 
of the red, though the proportion increases after eating. They are 
also rather larger than are the red corpuscles ; but their distinguish- 
ing characteristics (besides colourlessness) are their possession of 
a nucleus in their granular contents, and their spheroidal or irregular 
form. The white corpuscles, in fact, have the power of spontaneously, 
so to speak, altering their shape by protruding portions of their 
substance in an irregular manner and in all directions. This change 
of form is however effected very slowly, so that careful observation 
for several minutes, or several observations at intervals of about a 
minute, are needed to detect it. These movements are sometimes 
termed amoeboid, from their resemblance to the movements exhibited 
by some of the lowest animals. 

The blood, while within the body, during life, is really a tissue, 

* Which make up about a third of the volume of the mass of the blood. 



chap, vii.] THE CATS ORGANS OF CIRCULATION. 



195 



and as fully snares in the body's vitality as do the other tissues. 
The corpuscles may be regarded as answering to those nucleated 
cells which we have found to exist in the other tissues, while the 
liquor sanguinis corresponds with the matrix of such other tissues — 
the matrix being fluid in the blood tissue, instead of being calcareous, 
as is bone, chondrified as in cartilage, or more or less fibrous as in 
connective tissue. 

As has been already mentioned, the blood may appear either 
scarlet or purple, and from the relation of blood so diversely coloured 
to the parts which contain it, these two kinds of blood are spoken of 





Fig. 99.— Blood Corpuscles of Man and of the Cat, similarly enlarged. 



A. Blood corpuscles of man. 

B. Blood corpuscles of the cat. 
a. Red corpuscles. 

6. A single one seen edgeways. 

c. A few grouped in a pile. 

d. Normal white corpuscles. 



e. A white corpuscle treated with acetic acid 

and showing its nucleus. 
/. One slightly altered. 
g. A white corpuscle in the act of changing its 

shape by amcebiform movement. 



respectively as arterial and venous. The scarlet or arterial 
blood is found (1) in the arteries or vessels which carry blood from 
the heart as well as (2) in vessels which proceed from the lungs. 
The purple or venous blood is found (1) in the veins generally, (2) 
in certain vessels ramifying in the liver, and (3) in others proceeding 
to the lungs. 

The difference between arterial and venous blood depends upon 
arterial blood containing a greater quantity of oxygen, and venous 
blood possessing more carbonic acid. Blood contains a large amount 
of gas (about half its own volume), principally the gases just 
named, but also some nitrogen, introduced within it probably by the 
lungs. 

§ 3. Lymph is a slightly alkaline, clear, colourless, or pale yellow 
fluid, containing only 5 per cent., by weight, of solid constituents. 
It is thinner than blood, but, like it, contains albumen, some salts, 
and some extractive matters. It is devoid of red corpuscles, 
being in fact like the liquor sanguinis, and being, like it, capable of 
coagulation. It is in fact (as before said) made of the exudation of 
the liquor sanguinis mixed with fluid absorbed from the alimentary 
canal. Its likeness to blood is the more complete, since it contains 
numerous colourless corpuscles, " lymph corpuscles" and which are 
quite like the colourless corpuscles of the blood. 

o 2 



196 THE GAT. [chap. vn. 

The blood and lymph are contained and conveyed on their course 
by the various sets of vessels and other parts already enumerated, 
about each of which there is much to be said. 

§ 4. The arteries are strong and very elastic tubes, so that 
when empty they remain open and do not collapse. They are 
lined internally with an epithelial layer, external to which is a layer 
of elastic tissue. External to this again is a stratum of organic 
muscular fibres, arranged in bundles placed mainly at right angles 
to the course of tbe artery and tending to surround it, though some 
fibres are longitudinal and others oblique in direction. External 
again to the muscular layer is a layer of elastic tissue (and elastic 
fibres are also more or less mixed with the muscular fibres), ^nd 
finally the whole is enclosed by a layer of connective tissue. 

In the smallest arteries the elastic coat is absent, while the 
muscular coat is relatively more developed than in the larger 
arteries. Arteries, generally, run deeply in well protected situations. 
As they advance they divide and subdivide into smaller and smaller 
branches. Different branches of the same, or of different trunks, 
may unite together, and such unions are termed anastomoses. 
Arteries generally run in a rather straight manner, but they may 
pursue a very tortuous course. Sometimes an artery may suddenly 
break up into a number of small anastomosing branches, which 
reunite to form a single vessel. Such a network is called a rete 
mirabile. The presence of the muscular coat enables the arteries to 
diminish their capacit} r by contracting their muscular fibres, or, by 
relaxing them, to enlarge it, since these fibres are contracted to a 
certain moderate amount in the normal state of the arteries.* The 
walls of the arteries are themselves supplied and nourished by minute 
vessels termed vasa vasorum. 

§ 5. The veins are weak and thin-walled tubes , much less elastic 
tban the arteries — collapsing when emptied. They are* lined in- 
ternally with an epithelial layer, external to which is elastic tissue 
and a stratum of organic muscular fibres invested externally by 
connective tissue. 

, In some veins this muscular layer is absent, whi'e it is excep- 
tionally well developed in a large vessel going to the liver, the 
'portal vein, and in that coming from the spleen. The veins ramify 
through the body, as do the arteries, but are more numerous and 
have greater capacity. They are arranged in a superficial and 
deep set — the deeper veins accompanying the corresponding arteries, 
as what are called vena? comites. Veins anastomose together more 
frequently than do arteries ; their walls, like those of arteries, are 
supplied with vasa vasorum. 

The veins are generally furnished with certain structures not 
found in the arteries, namely, valves. These are crescentic folds of 
membrane, so arranged that in eich the semilunar edge of the fold 

* These muscles are under the control I the so-called vaso-motor and vaso-dilator 
of special parts of the nervous system — ' nerves. 



chap, vii.] THE CATS ORGANS OF CIRCULATION. 



197 



is continuous with the inner wall of the vein, while the straight 
edge of the fold hangs freely inwards into the cavity of the vein. 
Usually two such folds, or v.. Ives, are placed one opposite to the 
other, and when these hang down their free edges meet and so close 
altogether the passage through the vein. Any pressure exercised 
from that side towards which the concavities of the valves Lok, 
tends of course to separate them from the wall of the vein and so 
close the passage through it, while pressure from the opposite side 
tends to press the valves against the walls of the veins, and so to 




Fig. 100.— Diagrams, showing Valves of Veixs. 



A. Part of a vein cut longitudinally and opened 

out, showing two pairs of valves. On 
account of the vessel being thus opened 
out, each pair of valves appear as if placed 
side by side, instead of one opposite the 
other. 

B. Longitudinal section of a vein, showing the 

two valves of a single pair in their natural 
position, and showing the a] position of the 



edges of the valves in their closed state. 
The slightest pressure applied from below 
would cause these valves to open ; but 
pressure from above would only press them 
together more tightly. 

Portion of a distended vein, seen externally 
and exhibiting a swelling in the situation of 
a pair of valves. 



open the passage to its full width. Now these valves are so placed 
that their convexities look towards the capillary vessels, from which 
the vein which contains them springs, while their concavities look 
towards that print (generally the heart) towards which the stream 
of venous blood is flowing. Thus the action of these valves is to 
help on that stream along its course, since they readily yield and 
allow it to now along its appointed direction, whilst they descend, 
unite, and bar the passage, when temporary local pressure or any 
other cause tends to drive the blood in the reverse direction to that 
which it ordinarily pursues. 

There are no valves in the venae cavae, the portal and hepatic 
veins, those of the kidneys and uterus, nor in the pulmonary veins 
and those of the interior of the skull and vertebral column. 

§ 6. The veins and arteries are, as has been said, connected 
together by the intervention of the sanguineous capillaries. These 
are microscopic vessels and form a network in most of the tissues — a 
network so rich that sometimes the interspaces between them are not 
wider than are the capillaries themselves. Their walls are extremely 



198 THE CAT. [chap. vii. 

delicate, and readily allow their contents to exude. ■ It is only thus 
the un vascular tissues — such as dentine — are nourished. Besides 
the teeth, capillaries are absent from cartilage and from epidermal 
aud epithelial structures. 

The white corpuscles, pass readily through the walls of the minute 
capillaries, but the red corpuscles do so but rarely. Both veins and 
arteries merge insensibly into capillary vessels, and a constant stream 
of blood passes from the latter to the former through them. 

The smaller capillaries consist of a delicate membrane lined with 
endothelium ; the larger ones have also a layer of organic muscular 
fibres. 

§ 7. The lymphatics are present nearly everywhere in the body. 
They are smaller but more numerous than the veins, and anastomose 
more frequently. In some situations, as in the brain, they surround 
and enclose the blood-vessels, and they seem to take origin (as 
will be more fully pointed out when they are described,) in the 
mere interspaces between the elemental parts of different organs. 
When the lymphatics have advanced somewhat from their origin 
they possess three coats : namely, an inner one, of longitudinally 
disposed fibres of elastic tissue, lined with endothelium ; a middle 
one, of circular, organic, muscular fibres, mixed with elastic fibres ; 
and an outer coat of connective tissue— also with a few elastic 
fibres. 

Like the blood-vessels, the lymphatics have vasa vasorum in their 
walls. 

Valves, like those of the veins, exist in the lymphatics and 
lacteals. They are distributed at shorter intervals, and their 
structure is sometimes less regular. 

The lymphatics and lacteals in their course pass (as has been 
already observed,) through certain structures called lymphatic glands. 
These are rounded bodies, consisting mainly of a mass of lymph 
corpuscles enclosed in a firm envelope and richly supplied with 
blood-vessels and lymphatics. Each gland is coated externally by 
connective tissue (which may contain muscular fibre cells,) and 
which completely invests it, save where the vessels enter and leave 
it. This fibrous coat sends in processes, called trabecule, into 
the substance of the gland, which substance — the proper glandular 
substance — consists of a mass of lymph corpuscles, with connective 
tissue. The outer part of this mass (the cortical substance,) is 
generally enclosed in a number of chambers, alveoli, while the more 
central part (the medullary substance) is enclosed — like so many 
cords — between the meshes of the trabecule. In these chambers 
thus containing masses of lymph corpuscles, a certain space is left, 
called the lymph sinus or lymph-channel, which - space is crossed 
only by fibres of connective tissue, with their nuclei, and is traversed 
by the lymph stream. The lymphatics which come to the gland — 
the afferent lymphatics — lose all their coats as they enter, save the 
epithelial lining, which is continued on over the trabecule. Simi- 
larly the lymphatics which leave the gland — the efferent lymphatics 



chap, vii.] TEE CATS ORGANS OF CIRCULATION. 



199 



— begin to arise from the epithelial investment of the trabecule, and 
only acquire their coats, other than epithelial, as they leave the 
gland. # Thus^ a lymphatic gland is, as it were, an expanded 
sinus into which a number of lymphatics merge, and wherein it 
appears a multiplication of lymph corpuscles takes place, probably 
by spontaneous division — the parts of the corpuscles thus spontane- 
ously dividing growing up into whole corpuscles. 

Each gland is richly supplied with blood-vessels, and the lymph 




Fig. 101.— Diagrammatic Section of a Lymphatic Gland. 



at. Afferent lymphalics. 

el. Efferent lymphatics. 

c. Cortical substance 

m. Medullary substance. 

Is. Lymph sinus. 

c. Fibrous coat. 

tr. Trabeculae. 

llu Lymph corpuscles. 

The letter C is placed in one of the alveoli. The 
trabeculae are represented by a dark shade, 
and are seen extending inwards from the 
fibrous coat and as spots in the medullary 



substance— such spots being trabeculae cut 
across. At the upper right-hand part of the 
figure the lymph corpuscles, Ih, are repre- 
sented in three alveoli and in the adjacent 
medullary part. Elsewhere they are not 
represented. A whit • band is to be seen 
around all the alveoli, nd also round e^ch 
of the cut-across trabeculae in medullary 
substance. The band is the lymph sinus, 
a d the irregular lines wJiich cross it at 
short intervals are the connective 
fibres and nuclei. 



which leaves it is not only richer in colourless corpuscles than is 
that which comes to it, but also in fibrin. These glands are 
conspicuous in the neck, the axilla, and the thigh, and speedily 
enlarge in size when any part of the body near them becomes the 
seat of pain. 

§ 8. The heart is a thick muscular and hollow organ, from the 
anterior, broad part of which great blood-vessels originate. 

It is enclosed in a sac of fibrous tissue lined with epithelium, 
called the pericardium. It consists of four chambers, two of which 



200 



TEE CAT. 



[chap. VII. 



are called auricles, and the other two, ventricles— one of each on 
each side. The auricle and ventricle of the right side are com- 
pletely divided off from those of the left side. The auricles open, 
into the ventricles by valvular apertures, and valves guard the 
openings of the great vessels. 

Such being a summary of its main characters, its various parts 
need examination in detail. 

The heart of the cat lies on the ventral side of the body, within 




LV 




Fig. 102.— Cat's Heaett cut open. 



A. The left side. 

B. The right side. 

a. St} le passing up through inferior vena cava 

to right auricle. 
AO. Aorta. 

b. Style passing down from the vena azygos 

through superior vena ava into right auricle. 

c. Style passing down from the superior vena 

cava into the right auricle. 
CA. Conus arteriosus. 
cL Left carotid. 
cr. Right carotid. 

d. Style passing from conus arteriosus into left 

branch of pulmonary artery. 
ef. Style passing up from left ventricle into 

aorta. 
FO. Place where the foramen ovale existed in 

the foetus. 



g, h, i. Styles passing through pulmonary vein 

into left auricle. 
LA, Left auricle. 
LV. Left ventricle. 
MV. Mitral valve. 
n. Innominate artery. 
P^l L. Left branch of pulmonary artery. 
FAR. Right branch of pulmonary artery. 
FA. Righ auricle. 
F V. Right ventricle. 
si. Left sub-clavian artery. 
SL V. Semi-lunar valve. 
sr. Eight sub-clavian artery. 
TL. Tubercle of Lower. 
VCI. Inferior vena cava. 
VCS. Superior vena cava. 



the thorax, upon the inner surface of the sternum and between the 
two lungs. It is almost globular in shape, but slightly narrows 
towards its posterior end or apex, which touches the anterior 
surface of the diaphragm. 

At its opposite end, or base, the heart is connected with several 
great blood-vessels, but elsewhere its surface is free. 

The pericardium is a bag of dense fibrous tissue with an epithelial 
lining, and contain? — like the peritoneum — a serous fluid. This 



chap, vii.] TEE CATS OUGANS OF CIRCULATION. 201 

bag, the fibres of which interlace in all directions, adheres posteriorly 
to the anterior surface of the central tendon of the diaphragm, 
while anteriorly, it is attached to the outer coats of the great vessels 
which proceed to and from the heart, and is prolonged for some 
distance along their course. The internal, or serous, lining of the 
pericardium is (after lining the fibrous part forwards to its attach- 
ments) reflected back upon the outer surfaces of the great vessels 
just referred to, and closely invests the immediate outer surface of 
the heart, which is thus (like the roots of the great vessels) 
invested both by two layers of- serous, and by one of fibrous 
membrane. 

The external surface of the heart indicates its composition, since 
two longitudinal furrows indicate the separation of the heart into a 
right and left half, while a transverse furrow indicates the separation 
of each half of the heart into an anterior and a posterior portion. The 
anterior portion of each half is an auricle, and the posterior portion 
of each half is a ventricle. The auricular part of the heart (the 
two dorsal portions) is thin- walled and soft, and each portion bears 
a small appendage something like an animal's ear — whence the 
name "auricle." The two auricular appendages (one for each 
auricle) appear conspicuously on the anterior part of the heart. (See 
Fig. 104, RA and LA.) The ventricular part of the heart (the two 
ventricular portions) is thick-walled, firm and slightly conical from 
before backwards. 

§ 9. Great blood-vessels are connected with the anterior part 
of the heart as follows : — The anterior part of the heart is con- 
spicuously distinguished by two large arterial trunks proceeding 
from it contiguously, wdiereof the smaller and more dorsally situated 
arches backwards and to the left over the right-hand- branch of the 
two branches into which the larger and more anteriorly situated 
trunk divides. This more ventrally situated trunk proceeds 
obviously from the rigbt ventricle, it is the pulmonary artery, and 
its two branches just referred to go respectively to the right and 
left lung. The deeper or more dorsal trunk is the aorta, and a 
little further examination will show that it proceeds from the left 
ventricle. If now the heart be turned round, a large vein will 
be seen proceeding forwards to it on what is naturally the right 
side of the descending continuation of the arch of the great aorta. 
This vein is the vena cava inferior, and opposite to it— proceeding 
backwards to the heart from the front part of the body — is 
another vein, the vena cava superior, which passes backwards on 
the ventral side (the heart being in its natural position,) of tbe 
right branch of tbe pulmonary artery. These two great veins 
proceed to the right auricle. Other smaller veins (two on each 
side) are seen proceeding more or less horizontally inwards to the 
heart. These are the pulmonary veins, and they go to the left 
auricle. 

§ 10. The heart is diyided internally into four cavities corre- 
sponding with the four-fold division already noticed. 



THE CAT. 



[chap. vrr. 



The whole inner wall of the heart is lined with a layer of 
endothelium, which immediately invests a network of elastic fibres. 




Fig. 103.— Diagram of the Course of the Circulation, seen dorsally. 



Aa. Arteries to alimentary tube. 

AK Arteries to anterior parts of body and fore- 
limbs. 

A 2 . Arteries to hinder parts of body and hind- 
limbs. 

Al. Alimentary tube. 

Ao. Aorta. 

Ha. Hepatic artery. 

Hv. Hepatic vein. 

Let. Lacteals. 

Lg. Lungs. 

LA. Left auricle. 

Lr. Liver. 

LV. Left ventricle 

Ly. Lymphatics. 



PA. Pulmonary artery. 

P V. Pulmonary vein. 

PA. Right auricle. 

R V. Right ventricle. 

T. Thoracic duct. 

V 1 . Veins from anterior parts of body and fore- 
limbs. 

V s . Veins from posterior part of body and hind- 
limbs. 

VCI. Vena cava inferior. 

VCS. Vena cava superior. 

VP. Vena porta. 

The vessels which carry venous blood are dis- 
tinguished by shading. Arrows indicite the 
course of the blood-lymph and chyle. 



Thus the substance of the heart shows a similarity of structure to 
that of the vessels which might be expected, since its walls are 



chap, vii.] TEE CATS OBGANS OF CIRCULATION. 203 

directly continuous with the walls of the arteries and veins which 
open into it. The muscular fibres, however, of which the heart 
is composed are very numerous, forming a thick mass, and they are 
of the striated kind and of a deep red colour. Individually, never- 
theless, they are smaller than the ordinary striated fibres. They are 
also devoid of sarcolemma, and they often branch and anastomose. 

The fibres are arranged in layers disposed in various spiral curves 
around the cavities of the heart. The muscular walls of the ventricles 
are thicker than those of the auricles, and that of the left ventricle 
is again thicker than that of the right ventricle. Blood-vessels, 
nerves and lymphatics, with fat and areolar tissue, enter into the com- 
position of the heart, and fibrous andfibro-cartilaginous structures play 
important parts in its composition in connection with certain valves. 

These substances are so arranged that (as already remarked) a 
complete partition is formed between the right and left sides of the 
heart ; a septum entirely separating the cavities of the two auricles 
and the two ventricles respectively. Thus there is no direct 
communication between the ventricles, or between the auricles. 

The cavity of the right auricle however communicates not only 
with the interior of the vena? cava? which open into it, but also 
with that of the right ventricle, this latter opening being called the 
right auriculo- ventricular aperture. Besides this communication 
with the right auricle, the right ventricle only opens into the 
pulmonary artery. Similarly the cavity of the left ventricle com- 
municates not only with the interior of the pulmonary veins which 
open into it, but also with that of the left ventricle, this latter 
opening being called the left auriculo- ventricular aperture. Besides 
this communication with the left auricle, the left ventricle only 
opens into the aorta. 

§ 11. The course of the blood through the heart is as 
follows : — Yeuous blood is brought back by two large veins (the 
vence caves) from all parts of the body to the right auricle, whence it 
proceeds to the right ventricle. From the right ventricle it is 
carried to the lungs by the pulmonary artery and brought back 
from the lungs by the pulmonary veins to the left auricle ; from 
thence it proceeds to the left ventricle which distributes it, by 
the aorta, over every part of the body. 

Thus the blood, in its course to and from the heart, performs two 
different circuits. On the one hand, the whole of the blood passes 
from the right ventricle, through the lungs, and back to the left 
auricle, thus performing what is called the pulmonary circulation. 
On the other hand, the whole of the blood passes from the left 
ventricle all over the body, and thence back to the right auricle, 
thus performing what is called the systemic circulation. 

It is while passing through the lungs that the blood undergoes 
that process of gaseous interchange which makes it acquire a bright 
scarlet colour — the colour of normal arterial blood. On its way to 
the lungs it is of a deep purple tint — the colour of normal venous 
blood. Thus it comes about that the vessels which carry the blood 



204 THE CAT. [chap. vii. 

from the lungs to the heart carry bright scarlet or arterial blood, 
although they (inasmuch as they are vessels conveying blood towards 
the heart) are called " veins " — the pulmonary veins. Similarly, 
the vessels which carry the blood from the heart to the lungs contain 
dark purple or venous blood, although they (inasmuch as they are 
vessels conveying blood from the heart) are called " arteries " — the 
pulmonary arteries. 

§ 12. The current of the blood through the heart is kept up by 
the alternate contraction and dilatation of its four chambers, which 
is brought about by the successive contraction and relaxation of its 
various sets of muscular fibres. Its course through the heart is, 
however, determined by the action of certain valves which guard its 
most important apertures, and which, by acting like the valves of 
the veins, readily allow the blood to pass in one direction, while 
they oppose an effectual barrier to its passage in the opposite direc- 
tion. The valves which most resemble those of the veins are the 
valves which are placed at the root of the aorta and pulmonary 
artery. These are called semilunar valves, and there are three in 
each vessel. They consist of processes of fibrous tissue (invested 
with endothelium), and each is continuous by one curved edge with 
the wall of the artery, while the other edge hangs freely so far out 
from the wall of the vessel that the whole three valves, when so 
hanging, meet together (by a tri-radiate suture), and form a complete 
partition across the vessel. The margin of each valve is strengthened 
by a tendinous band, and at its middle is a small fibro-cartilaginous 
nodule called a corpus Aurantii. 

While the blood is flowing from the contracting ventricles, these 
valves lie back against the inner walls of the arteries, but when the 
ventricles dilate and the elasticity of the arterial walls tends to drive 
the blood back into the ventricles, these valves immediately descend, 
and the greater the pressure from above, the more completely and 
accurately do they close together. 

At the roots of the pulmonary veins there are no valves, and there 
is only a rudimentary one at the root of the vense cavse. At each 
of the auriculo-ventricular openings, however, there is a valve of 
complex structure, consisting of membranous flaps, with delicate 
tendinous cords {chordae tendinece) attaching them to papillary pro- 
longations inwards — column® carnece — of the muscular ventricular 
walls. 

The valve of the right auriculo-ventricular aperture is called the 
tri-cuspid valve, because it consists of three segments. The delicate 
tendinous cords above named proceed partly from the walls of the 
ventricle (especially the septum), but mainly from little muscular 
prominences — the columnse carnese. The tendinous cords are so 
distributed that some of those from each origin proceed to the edge 
of one valve, while the others proceed to the adjacent edge of another 
valve — thus diverging as they advance (Fig. 102, B). 

The valve of the left auriculo-ventricular aperture is called the 
bi-cuspid or mitral valve, and consists but of two segments. It is 



chap, vii.] THE CAT'S ORGANS OF CIRCULATION. 205 

much thicker and stronger than the tri- cuspid valve, but its essential 
arrangement is the same. 

The action of the tri- and bi~ cuspid valves is similar, and is 
inverse to that of the semi-lunar valves. When the auricles 
contract and the blood tends to flow into the ventricles, these 
valvular flaps readily bend backwards and allow it free passage ; 
but when, by the contraction of the ventricles, the blood tends to be 
driven into the auricles as well as into the great arteries, then these 
valves immediately close, and are pressed towards the auricles, while 
they are prevented from going too far (and so being driven into the 
auricles) by the numerous chordae tendinese which hold them firmly 
attached, as the cords of a tent hold and sustain it. The exactness 
with which they meet together is rendered complete by the columnm 
carnece themselves, which participate in the contraction of the cavity 
from the walls of which they proceed. 

§ 13. The right auricle (Fig. 102, B, RA) is situated at the 
ventral side of the base of the heart, and has a smooth surface. 
The superior vena cava (which is very short) opens into the anterior 
portion of this chamber, and the inferior vena cava opens by a larger 
opening into its posterior part — above the auriculo- ventricular 
aperture — while between them is the orifice of a small vein called 
coronary^ which brings back the blood from the walls of the heart 
itself. This part of the cavity (as distinguished from the cavity of 
the auricular appendage) is called the sinus venosus. At the hinder 
part of the septum, which divides this auricle from the left one, is 
an oval depression called the fossa ovalis (FO), which is the indica- 
tion of a foetal condition, for, as we shall see, in the embryo an 
opening leads directly from one auricle to the other. Immediately 
in front of this is a marked transverse prominence called the tubercle 
of Lower (TL). 

The left auricle, which, when distended, has a somewhat 
quadrangular appearance, lies to the left on the dorsal aspect of the 
base of the heart. The openings into it of the pulmonary veins are 
dorsally placed, and there are usually two on each side. Those of 
the right side, however, meet together close to the auricle, so that 
there seems to be but one pulmonary vein opening into it on that 
side. The wall of the septum shows a slight depression, correspond- 
ing with the fossa ovalis of the right auricle. 

The right ventricle forms the right side of the ventral aspect 
of the heart from the transverse furrow onwards towards its apex. 
Internally it presents the valvular structure (the tri cuspid valve) 
already described, but its upper and anterior part is smooth and 
free from columnaa camese. It is also prolonged forwards in a 
conical manner, whence this part has been named the conas 
arteriosus (CA). The left wall of the ventricle is convex, the septum 
between the ventricles so bulging into its cavity as to make that 
cavity appear crescentic when the right ventricle is transversely 
bisected. The muscular wall of this chamber is much thicker than 
that of either of the auricles. The opening (with its semi-lunar 



206 THE CAT. [chap. vii. 

valves) which leads into the pulmonary artery is remote from the 
auriculo -ventricular opening. 

The left ventricle, by far the thickest-walled portion of the 
heart, extends backwards to its apex mainly on the posterior aspect 
of the organ. The side which is formed by the septum is concave 
instead of convex — the transverse section of the cavity of thi:, 
ventricle being oval. The opening (with its semilunar valves) 
which leads into the aorta is close beside the auriculo- ventricular 
opening, but to the right, and somewhat ventrally to the latter. 

The coronary arteries, which convey the blood for the nutrition of 
the substance of the heart, do not lead from the cavity of the 
ventricle itself, but from the aorta (one opening on each side) 
immediately in front of the attachment to it of its semi-lunar valves. 

§ 14. All the arteries of the body, with the exception of the 
pulmonary artery and its branches, are larger or smaller ramifica- 
tions of that great artery, called the aorta; and all without exception, 
therefore, are ramifications of vessels which proceed directly from 
one or other of the ventricles of the heart. Those which proceed 
from its right side, are the arteries of the pulmonic circulation, 
and carry venous blood; those which proceed from its left side, are 
arteries of the systemic circulation, and carry arterial blood. 

The pulmonary artery is the most capacious vascular trunk in 
the body, but is very short. Arising from the conus arteriosus, it 
passes dorsally and to the left, and then bifurcates. One branch 
passes to the right, above the arch of the aorta. It then divides 
and sub-divides within the right lung. The other branch passes 
to the left, beneath the dorsally and posteriorly- extending part 
of the aortic arch, and then divides and sub-divides within the 
left lung. Each pulmonary artery, at the root of the lung, lies 
dorsally to the pulmonary veins, and ventrally to the air-tube or 
division of the windpipe, which there enters the lungs. A little to 
the left of its bifurcation, the pulmonary artery is connected by a 
fibrous band with the concavity of the aortic arch. This band is 
the relic of a foetal tubular structure, which in the embryo places 
the cavities of these two great arteries in direct communication,, and 
is then called the ductus arteriosus (Fig. 104, da). 

§ 15. The aorta springs from the base of the heart, rather 
dorsally to the pulmonary artery and between the anterior ends of the 
two auriculo-ventricular apertures. It arches to the left, over the 
right branch of the pulmonary artery, and over the root of the left 
lung, till it reaches the front— ^.£., the ventral side of the vertebral 
column. Thence it passes backwards through the hinder margin of 
the diaphragm, and ends by dividing into the iliac arteries, which 
go to the pelvic viscera and pelvic limbs. 

The aorta is, as it were, the axis of the systemic arterial system ; 
and (apart from small branches and large vessels given off to the 
abdominal viscera) may be said to give off eight branches or sub- 
divisions, four being anterior and four posterior. Of the four 
anterior branches, one goes to each pectoral limb and one to each 



chap. vii.J THE CATS OBGANS OF CIRCULATION. 



207 



side of the head. The four posterior "branches are the iliac 
arteries already referred to. Besides the aortic arch, the rest of its 
course, which is called the descending aorta, is sub- divided into the 
part in front of the diaphragm and the part below it — i.e., into the 
thoracic and the abdominal aorta. 

The arch of the aorta gives off, almost from its very starting 
point — as before mentioned — the coronary arteries (which go to 
the heart itself), and afterwards the four great vessels (which 




Fig. 104.— The Heart, great Vessels and Lungs of the Cat ; Ventral aspect. 



Ao. Arcli of aorta. 
CC. Carotid arteries. 
Da. Ductus arteriosus. 
LA. Left auricle. 
LV. Left ventricle. 
PA. Pulmonary artery. 
JIA. Right auricle. 
RV. Right ventricle. 
T. Trachea. 
IV. Vena cava inferior. 



VS. Vena cava superior. 
Vc. S. Vena azygos. 

1. Upper lobe "of right lung. 

2. Second lobe of right lung. 

3. Third lobe of right lung. 

4. Fourth or lowest lobe of right lung. 
4a. Partly separate portion of fourth lobe. 

5. Upper lobe of left lung. 

5n. Partly separate portion of the same. 

6. Lower lobe of lef\ lung. 



go to the head and fore-limbs) by two very unequal trunks. One of 
these, the larger, and placed on the right, is called the innominate 
artery. (Fig. 102, n.) It soon gives off a large branch (cl), which is 
the left carotid artery ; and the remaining part, almost immediately 
bifurcates into the right carotid and the right sub-clavian arteries. 



208 THE CAT. [chap. vii. 

The second and much smaller vessel given off from the arch of the 
aorta, is the root artery of the arteries of the left fore-limb — i.e., it 
is the left sub-clavian artery (si). After giving this off, the aorta 
passes upwards as the thoracic part of the great dorsal (in man, the 
" descending") aorta. It gives off a number of branches, which 
will be referred to shortly. 

§ 16. The two carotid arteries pass forwards along the neck, 
one on the right and the other on the left side of the trachea and 
oesophagus, to the head. Each gives off in succession the following 
branches : — Each gives off a rather large artery to supply the muscles 
of the side of the neck ; and, opposite to this, a small branch to the 
lymphatic gland lying on the middle of the trachea. Next comes the 
thyroid artery, which goes to the thyroid cartilage, and to a structure 
to be hereafter described as the thyroid gland. It then gives off (from 
its opposite side) another artery to the muscles of the neck, and (almost 
opposite this) a very large Ungual artery, which passes dorsally to the 
basi-hyal, beneath the stylo -glossus, and goes to the under surface of 
the tongue. The carotid next gives off a small facial artery, which 
sends out branches to the cheek, and ends in the upper and lower 
lips. A small branch goes to the sub-maxillary gland, starting 
from the very root of the facial artery. The carotid artery then 
makes a sharp bend, and gives off backwards a branch to the 
parotid gland ; and then, at the further end of the curve, another 
branch, which also goes in part to the parotid gland, and a part to 
the muscles of the temporal fossa. This arched part of the carotid 
ends anteriorly, close to the anterior margin of the glenoid surface. 
The carotid then breaks up into a plexus of minute branches, which 
run side by side under the eye-ball, and over the orbital plate of the 
maxilla. From this plexus minute arteries are given off, such as 
the ophthalmic, ciliary, ethmoidal and meningeal arteries. 

The ophthalmic artery passes along the inner side of the orbit, 
giving off branches to the lachrymal gland, the forehead and muzzle, 
the eye-ball and nasal cavity, the latter being called the ciliary and 
ethmoidal arteries. 

The meningeal artery supplies the dura mater. It enters the 
skull from the plexus, through the sphenoidal fissure. 

The nasal artery is a small branch which passes through the 
spheno- palatine foramen (in company with the nasal nerve), and 
continues on, skirting the nasal septum. 

The carotid also gives off the superior dental artery, which enters 
the maxilla posteriorly, and supplies the upper teeth. Finally, the 
carotid passes through the infra-orbital foramen, and terminates as 
the infra-orbital artery, which distributes its branches about the 
face. 

A very minute vessel, called the internal carotid, is given off 
from the main carotid in the vicinity of the foramen lacerum 
posterius. It enters that aperture, and passes along a slender canal 
between the basi-occipital and basi-sphenoid, and the adjacent part 
of the temporal bone. It then enters the cranial cavity on the 



chap, vil] THE CAT'S ORGANS OF CIRCULATION. 209 

inner side of the anterior end of the petrous part of the temporal 
bone, and unites with the circle of Willis, formed by the branches of 
the basilar artery The internal carotid artery is so minute that it 
would not be worthy of note were it not for its large size in man and 
many other animals. 

§ 17 The subclavian artfry is the root artery of the fore-limb- 
That of the right fore-limb springs from the larger branch of the 
innominate artery. That of the left fore-limb takes origin directly 
from the arch of the aorta. 

The subclavian artery first approaches the clavicle, and then, 
arching over the first rib, recedes to the axilla and becomes the 
axillary artery. 

The first branch given off by the -subclavian is the vertebral artery. 
It bends rather sharply upwards to pierce the transverse process of 
the sixth cervical vertebra. It then advances through the perfora- 
tions of the other cervical transverse processes, till, having traversed 
that of the axis, it bends at a right angle to reach the notch between 
the transverse process and the anterior articular process of the same 
bone. It then traverses the atlas, and, finally, entering the cranium 
through the foramen magnum, it unites (on the upper surface of the 
basi- occipital) with its fellow of the opposite side to form the basilar 
artery. 

The basilar artery runs forwards as a long single vessel, gives off 
a branch on each side, and then continues on to form a circular 
vessel around the infundibulum and pituitary body in its sellu 
turcica. This circular vessel is the circle of Willis, already men- 
tioned; the internal carotids unite with it, and branches to the 
brain are given off anteriorly and laterally from it. 

The second branch given off from the subclavian on the same 
side as the vertebral, is the thyroid axis. It arises covered in by 
the scalenus muscle, and arches forwards and upwards over the 
scapula — sending a braDch up to the thyroid body. 

A considerable vessel, the internal mammary artery, is given off 
directly opposite to the thyroid axis. It passes backwards along 
the inside (dorsal surface) of the cartilages of the ribs. It gives 
off a long and very slender branch, called the superior phrenic, 
which passes backwards to the diaphragm between the lung-root 
and the pericardium. 

The superior intercostal artery, extends along the inside of the first 
three ribs, supplying the intercostal muscles. About half-an-inch 
beyond the origin of the thyroid axis a second artery is given off, 
which arches forwards and upwards over the scapula. 

§ 18. The subclavian becomes the axillary artery as it passes 
into the axilla, between the pectoralis, subscapular, and latissimus 
dorsi muscles, surrounded by the nerves of the brachial plexus. It 
gives off various branches, as follows : the superior thoracic, which 
goes to the pectoral muscle ; the acromial thoracic, which is large and 
divides into advancing and receding branches which respectively supply 
the deltoid, pectoralis and serratus magnus muscles ; the long thoracic 



210 THE CAT. [chap. vii. 

and alar-thoracic arteries, which go respectively to the thoracic 
muscles and axillary lymphatic glands ; finally, the anterior and 
posterior circumflex arteries (the latter being very large) which pass 
round and embrace the uppermost portion of the humerus. 

Below the axilla the axillary artery takes the name of brachial, 
and descends to the elbow between the biceps, the coraco-brachialis, 
and the brachialis anticus muscles. It gives oft' a branch called the 
superior profunda artery, which accompanies the muscular spiral 
nerve and winds round the back of the humerus to its outer lower 
part. Another branch, the inferior profunda artery, is given off 
lower down, and passes to the inner side of the ]ower part of the 
arm — in company with the ulnar nerve. Having passed through 
the internal condyloid foramen and reached the concavity of the 
elbow, the brachial artery divides into two branches, called the 
radial and ulnar arteries. 

The ulnar artery (which is much smaller than the radial) passes 
along on the ulnar side of the flexor surface of the fore-arm (beneath 
the pronator teres, flexor carpi radialis, palmaris longus, and flexor 
sublimis muscles) into the palm, when it joins a branch of the radial 
artery to form a loop called the palmar arch. 

Soon after its origin the ulnar artery gives off a branch called 
the interosseous artery, which descends along the anterior surface 
of the interosseous membrane. 

The radial artery continues on the line of the brachial artery, 
and extends along the flexor aspect of the radius to the wrist, when 
it turns to the dorsal surface of the fore-paw and then penetrates 
between the second and third metacarpal bones, and unites with a 
branch of the ulnar artery to form a palmar arch. The radial artery 
is more superficial than the ulnar, being only overlapped by the 
supinator longus muscle. The palmar arch gives off a very small 
artery to the pollex and larger ones, which subdivide and go to the 
four other digits. 

§ 19. The thoracic aorta passes backwards to the left and 
ventral side of the vertebral column extending to the diaphragm, 
after perforating which it becomes the abdominal aorta. It lies in 
the posterior mediastinum (or dorsal space between the lungs) 
beside the oesophagus. It gives off many small arteries, such as the 
bronchial arteries (to nourish the lungs and the air- tubes), those of 
the oesophagus and intercostal arteries, which supply those intercostal 
spaces which are not supplied by the intercostal branch of the sub- 
clavian. Each intercostal artery passes along the posterior margin 
of a rib on the deep surface of the external ^intercostal muscle. The 
vessels of the right side have, of course, to cross transversely the 
ventral surface of the vertebral column. Each intercostal also gives 
off a small posterior or dorsal branch, which ascends, inside the ante- 
rior costo- trans verse ligament, to the muscles of the back. The two 
hindmost intercostals on each side are rather lumbar than dorsal 
arteries, since they traverse the trunk behind the last rib. 

The abdominal aorta is the continuation backwards, beyond the 



chap, vil] THE CAT'S ORGANS OF CIRCULATION. 211 

diaphragm, of the thoracic aorta. It gives off certain noteworthy 
branches — the inferior phrenic, lumbar, cceliac, mesenteric, supra- 
renal, renal, and spermatic (or ovarian) arteries — and then ends by- 
dividing into five parts, namely, its really posterior termination, 
the caudal, or inferior sacral, artery, and the two internal and two 
external iliac arteries. 

The inferior phrenic, which is exceedingly small, goes to the 
hinder surface of the diaphragm, and gives off a branch which 
extends along the psoas. The lumbar arteries continue on back- 
wards, the series of intercostals quite resembling the last two of the 
latter, which go to the lumbar region. They also give off a dorsal 
branch, which passes upwards between the transverse processes of 
the vertebra. The main trunk of each runs down amidst the 
abdominal muscles, which it supplies. The cceliac artery, or cceliac 
axis, is a short and wide vessel which arises close to the diaphragm, 
and quickly divides into three important visceral branches : 

A. The first of these is the coronary artery of the stomach, which 
extends along the smaller curvature of the stomach from its 
cardiac orifice. 

33. The second of these is the hepatic artery, which passes up- 
wards to the transverse fissure of the liver, where it divides and 
ramifies in the substance of the liver in the portal canals, along 
with the portal vein and hepatic duct. 

C. The third branch' of the cceliac axis is the splenic artery, which 
extends to the left above the pancreas to the spleen, giving off, 
however, some twigs to the cardiac surface of the stomach. 

A fourth branch may go to the right supra-renal capsule. 

The superior mesenteric artery is a very large vessel supplying the 
whole small intestine (except the duodenum), together with the 
ccecum and first part of the large intestine. It subdivides (to go to 
the intestine) in the folds of the peritoneum. 

The inferior mesenteric artery is very much smaller than the artery 
last described. It passes out between the mesenteric peritoneal folds 
to the hinder part of the large intestine. 

The capsular or supra-renal arteries, are very small. They arise, 
one on each side, near the superior mesenteric artery, and pass 
obliquely outwards, to organs hereafter to be described as the supra- 
renal capsules. 

The renal arteries (Fig, 105, a) are exceedingly large, but short. 
They are two in number, and they pass out, one on each side, 
horizontally from the aorta, a little behind the superior mesenteric 
artery (that of the right being a little the more posterior, and, from 
the relation of the aorta to the spine, the longer), and go to the 
kidneys, each dividing into four or five branches before it penetrates 
the kidney, in the substance of which it ramifies, as will be hereafter 
described. 

The spermatic, or ovarian arteries, are also two in number, 
but each is very long and exceedingly slender. They arise side by 
side, a little behind the renal arteries, from the ventral aspect of the 

p 2 



212 



THE CAT. 



[chap. VII. 



aorta. Each passes backwards and outwards, over the psoas muscle, 
to the internal abdominal ring, through which, in the male, it 




Fig 105.— Abdomen of a Female Cat opened, and with the Stomach, Intestines, and 
Liver removed, so as to show the Kidneys, Uterus,. Bladder, and Great 
Blood-vessels in position. 



a. Renal artery. 

ao. Aorta passing through the diaphragm. 

6. Bladder. 

c. Right cornu of uterus. 

d. Part of the diaphragm with the opening for 

the vena cava. 
/ Fallopian tube. 
i. Left iliac arteries, showing the distinct origin 

from the aorta of both the external and 

internal iliac, 
fc. Kidney of left side. 



I. Lymphatic vessel. 

o. Ovary of right side. 

ov. Ovarian vessels of right side. 

r. Rectum, cut across behind the body of the 

uterus, 
sr. Supra-renal capsule of right side, 
w. Ureter of right side, proceeding from kidney. 
u* Ureter of left side entering bladder. 
%t. Uterus. 
v. Renal vein. 
vc. Vena cava inferior cut across above. 



descends to the testicle. In the female, the vessel inclines inwards, 
and passes, between the folds of the broad ligament, to the ovary. 
§ 20. The iliac arteries. — Having reached nearly the hinder end 



chap. vn.J THE CAT'S ORGANS OF CIRCULATION. 213 

of the abdominal cavity, the aorta gives off two large arteries which go 
one to each hind limb respectively, and each of which is named an 
external iliac artery. After continuing on fur a short space further, 
the aorta gives off another pair of rather smaller vessels called the 
internal iliac arteries (Fig. 105, i) ; the aorta then immediately bends 
sharply upwards, and thenceforth continues onwards, gradually 
narrowing, beneath the middle of the tail as the caudal artery, which 
gives off twigs to the caudal muscles. 

The internal iliac, or hypogastric artery, dips down into the 
pelvis, and gives off a variety of branches. Amongst them we have 
the superior vesical, which goes to the side of the bladder, and is con- 
nected with the umbilicus (or navel) by a fibrous cord — a relic of 
an important fcetal structure ; the inferior vesical, which goes to the 
bladder, and, in the male, to a part to be hereafter described as the 
prostate gland ; the uterine and puclic arteries, which go to the uterus 
and external generative organs ; the gluteal artery, which passes out 
of the pelvis, between the pyriformis and gluteal muscles, supplying 
the latter ; and the sciatic artery, which passes out of the pelvis at the 
great sciatic notch, and goes (between the greater trochanter and the 
tuberosity of the ischium) to the muscles of the hip and thigh. 

§ SI. The external iliac artery is very conspicuous on the 
inside of the thigh. It passes backwards, downwards, and outwards, 
and soon gives off a large branch called the obturator artery, which 
passes out of the pelvis through the obturator foramen. From the 
obturator artery is given off the epigastric artery, which passes for- 
wards in the middle of the abdominal wall, and anastomoses with 
branches of the internal mammary artery. 

Having passed beneath Poupart's ligament to the thigh, the ex- 
ternal iliac assumes the name of the femoral artery, and descends 
along the inside of the thigh, resting successively on the psoas, 
pectineus, and adductor muscles. Near its origin, the femoral gives 
off a large branch called the deep femoral, which passes in through 
the adductor muscle, and ramifies in the muscles of the hinder and 
outer parts of the thigh. 

Before reaching 'the back of the knee-joint, the femoral artery 
divides into the anterior and 'posterior tibial arteries. 

The posterior tibial artery runs down behind the tibia, upon 
the tibialis posticus and flexor longus digitorum muscles, to the inner 
side of the os calcis, where it divides into the external and internal 
plantar arteries. The first of these goes to the base of the fifth 
metatarsal, and then passes obliquely between the metatarsals to 
anastomose with the dorsal artery of the foot, so forming a plantar 
arch. The second, or internal plantar, proceeds along the inner side 
of the sole of the foot towards the index. 

The posterior tibial gives origin to a branch called the peroneal 
artery, which descends behind the leg close to the fibula, and in 
contiguity with the flexor longus hallucis to the outside and back of 
the os calcis. 

The anterior tibial artery passes forwards to the front of the 



214 THE CAT. [ CH ap. vii. 

inter- osseous membrane. It then turns downwards and passes to the 
middle of the front of the ankle, where it assumes the name of 
dorsal artery of the foot, and runs on between the metatarsals of the 
index and middle digits, where it divides, one part sinking to 
anastomose with the external plantar artery (as already mentioned), 
and the other part going to the inner side of the foot. This and the 
plantar arteries give off small vessels to the digits, similar to those 
given off to the digits in the fore-paw. 

§ 22. The veins are, with ^ the exception of the portal vein, 
afferent vessels beginning by minute tubes, which converge and unite 
to form larger and larger trunks. They cannot, like the arteries, 1 
be grouped in only two sets of vessels — those of the pulmonary and 
of the systemic circulation respectively — because there are veins 
which belong to a third category, already noted as those of the 
portal circulation, which ramify and distribute the venous blood 
from the spleen, pancreas, stomach, and intestine, within the sub- 
stance of the liver. With the exception, however, of the veins of 
the pulmonary and portal circulations, all the veins of the body are 
larger or smaller tributaries to those great vessels, already more than 
once referred to as the superior and inferior venae cavse, and which 
open directly into the right auricle of the heart. The veins which 
pass from the lungs to the left auricle, are those of the pulmonary 
circulation ; while those veins which arise in the spleen, pan- 
creas, stomach, and intestine, and those which ramify within the 
Substance of the liver, together constitute the portal system. The 
whole of the blood passes at each circuit through both the pulmonary 
and systemic circulations, but only a portion of the blood has a share 
each time in the portal circulation. Thus both the systemic and 
pulmonary circulations are served both by arteries and by veins, 
and in each the blood is in one part arterial and in another venous, 
but the portal circulation is served by veins only, and its blood is 
venous entirely throughout. 

There is yet another antithesis : in both the systemic and pul- 
monary circulations the circuit is complete, the vessels being 
connected together by capillaries, as well as by large trunks. The 
portal circulation is incomplete in so far as it is connected by minute 
vessels only, there being no direct connexion between the large trunks 
which send blood to, and those which receive it from, the liver. 

The pulmonary veins are the only veins which convey arterial 
blood. They arise by minute branches in the lungs (as will be 
again noticed with the description of the breathing organs) ; they 
converge to form four vessels, two on each side in the root of each 
lung. These empty themselves into the left auricle. Those of the 
right side pass behind the right pulmonary artery and on the dorsal 
side of the vena cava superior and the aorta. Those of the left side, 
which are the shorter, pass ventrally to the descending aorta. 

The pulmonary veins of the right side unite with one trunk just 
before opening into the auricle. 

As has been before said, many of the systemic veins consist of a 



chap, vil] THE CAT'S ORGANS OF CIRCULATION. 215 

double set, one deep and one subcutaneous. They moreover com- 
municate and anastomose together more frequently than do the 
arteries. The systemic veins are naturally divisible into (1) those 
which ultimately pour themselves into the vena cava superior, and 
(2), those which convey blood to the vena cava inferior. To the 
first category belong the veins of the head, the pectoral limbs, the 
vertebral column, and part of the thoracic and abdominal walls. To 
the second category the veins of the pelvic limbs, of the lower part 
of the trunk, and of the abdominal viscera. 

The veins of the outside of the cranium and face converge to form 
the temporal, internal maxillary and facial veins ; the temporal passes 
through the parotid gland and becomes (having united with the two 
others), the external jugular vein (see Fig. 88), which, be- 
ginning at the mandibular angle, descends, crossing the sterno- 
mastoid muscle, to the great subclavian vein. 

The blood from the brain and inside of the cranium -collects in 
reservoirs called the cranial sinuses, which groove the inner surfaces 
of the bones of the skull.* The blood from all these sources 
collects at the opening called the foramen lacerum posterius or 
jugular foramen, and the vein which passes out through it, receives 
the name of the internal jugular vein, which vein descends 
outside and parallel with the common carotid artery, till it joins the 
subclavian vein (the junction being furnished with a valve), when 
the two, by their union, form the right innominate (or brachio- 
cephalic) vein. 

The veins of the digits, fore-paw, and arm of each side, partly 
unite to form a sub-cutaneous network, which ends in larger channels 
(radial, ulnar, and median), which unite and end, sooner or later, 
in the axillary vein. 

The veins of the digits, fore-paw, and arm, also unite to form a 
deep set'of veins which accompany, as fence comites, the tributaries 
of the brachial vein, uniting .and ending ultimately in a single trunk, 
the axillary vein, which, as it passes over the first rib, assumes 
the title of subclavian, and receives the contribution of the external 
jugular vein, as already mentioned, as also that of the vertebral 
vein, which descends through the canal of the cervical transverse 
processes in company with the ascending vertebral artery, Near 
the clavicle, the subclavian vein unites with the internal jugular to 
form the innominate vein already mentioned. Finally, the in- 
nominate vein unites with its fellow of the opposite side to form the 
vena cava superior, which passes down in front of the pulmonary 
vessels of the right side, and to the right of the aorta, to the right 
auricle. 

Yalves are found in the veins of the pectoral limb generally, but 
especially in the deep veins. 

The veins of the digits, hind-paw, and leg of each side, also partly 

* The middle of the skull root and the occipital and temporal bones as already- 
described, see ante, pp. 62 and 66. 



216 THE CAT. [chap. vii. 

unite to form a subcutaneous network, which ends in two main 
channels. The larger of these, the saphenous vein, runs up the 
inner side of the foot, leg, and thigh, beneath the skin, and 
terminates in the femoral vein. 

The veins of the toes, hind-foot, and leg, also unite to form a deep 
set of veins, which accompany the arteries as venae comites, and 
which are more richly supplied with valves than the superficial 
veins. The various tributaries ultimately unite to form the 
femoral vein, which, as it passes beneath Poupart's ligament 
with the femoral artery, assumes the title of external iliac 

VEIN. 

Meantime, the small veins of the pelvic viscera unite into larger 
vessels, generally corresponding with the divisions of the internal 
iliac artery (except that there is no remnant of any foetal venous 
structure, save that going to the liver as the "round ligament"), 
and ultimately unite in a large valveless vessel called the internal 
iliac vein. The external and internal iliac veins unite to form a 
single vessel — the vena cava inferior. 

This vena cava inferior is very much longer than the superior 
vena cava, and advances on the right side of the descending aorta. 
It then bends downwards, perforates the diaphragm, and ends in the 
right auricle. As it advances from its origin it receives important 
accessions, corresponding, to a certain extent, with branches directly 
given off from the abdominal aorta. They are : — 

The caudal vein, which is really the posterior commencement of 
the loAver vena cava, as the caudal artery is the real termina- 
tion of the aorta. 

The lumbar veins. 

The phrenic veins. 

The spermatic veins. 

The renal veins. 

The capsular veins. 

All these sets of veins correspond with the similarly-named 
arteries, but there are no veins entering the vena cava which 
correspond with the superior and inferior mesenteric arteries, or 
with the cceliac axis, but veins enter it directly, which are called 
hepatic, though they do not correspond, either in situation or distribu- 
tion, with the hepatic artery. They do not correspond in situation, 
because they enter the vena cava anteriorly to the point at which 
the cceliac axis (of which the hepatic artery is a branch) quits the 
aorta. They do not correspond in situation, because the hepatic 
artery enters the liver at its transverse fissure, and ramifies in the 
portal canals, while the hepatic veins run in quite differently directed 
channels, and converge to the groove in the dorsal margin of the 
liver, in which lies the vena cava, into which vessel they directly 
empty themselves. The hepatic veins are valveless. 

§ 23. The veins which correspond with the mesenteric arteries, 
and with the branches of the cceliac axis, constitute the portal 
system. Thus we have the superior and inferior mesenteric veins, 



chap, vil] THE CAT'S ORGANS OF CIRCULATION. 217 

which, converge as the corresponding arteries diverge, and empty 
themselves into the splenic vein, which returns blood from the 
pancreas as well as from the spleen, and also a vein from the 
stomach along its greater curvature. 

The veins thus- converging form the portal vein. This portal 
vein passes to the transverse fissure of the liver above the hepatic 
artery and duct, enclosed in the gastro-hepatic omentum. Arrived 
within the fissure, it divides right and left, and ramifies in the right 
and left portions of the liver, forming the great vessel of each portal 
canal. The portal vein is without valves. 

§ 24. Another system of venous structures goes by the name of 
the azygos vein, although there are really a pair — one on each 
side. They are elongated vessels advancing one on each side of the 
spine, but more or less irregular in form and arrangement, They 
are formed by the union of the intercostal veins (corresponding with 
the intercostal arteries) and are tolerably symmetrical behind, but 
anteriorly some of the veins of the left side of the body, though not 
those of the three or four upper intercostal spaces, are poured into 
the right azygos vein, which thus becomes enlarged. 

They begin behind in the lumbar veins, and the right azygos vein 
advances and passes through the diaphragm, with or near the aorta, 
till near the root of the right lung, where it turns downwards and 
empties itself into the vena cava superior (Fig. 104, vz), very near 
the right auricle. 

The left azygos vein also commences with the lumbar veins, 
advances and passes through the diaphragm, with or near the aorta* 
and remaining very slender, ends by opening into the left innominate 
vein. The azygos veins have valves. 

The veins of the heart itself open into the . right auricle between 
the auriculo-ventricular opening and that of the vena cava 
inferior. 

Thus the heart may be said to have a small circulation of its own — 
in addition to the systemic, pulmonary and portal circulations already 
mentioned. For blood from the coronary arteries * flows from the 
root of the aorta to the substance of the heart, whence it is directly 
returned by these coronary veins. 

§ 25. The lymphatics or absorbent vessels (including the alimentary 
lacteak,) seem to arise by minute vessels in every part of the body, 
which form a system of tubes (of different sizes,) and reservoirs (or 
sinuses). 

Some of these latter are much dilated, for the great peritoneal 
sac, with the other serous sacs — including those investing the 
nervous centres — are to be regarded as being really large lymphatic 
sinuses or interspaces, because the lymphatic vessels communicate 
with the peritoneal cavity by definite apertures called stomata. 
Thus the lymphatic system is not so closed a system as is the 



See ante, p. 206. 



218 THE CAT. [chap. vii. 

sanguineous system. It is not so because the peritoneal cavity 
communicates (in the female cat) directly with the exterior by means 
of the Fallopian tubes, while the sanguineous system only commu- 
nicates with it indirectly through the opening into it of certain 
lymphatic vessels. The mode in which lymphatic vessels ab- 
solutely commence is a matter not yet satisfactorily ascertained, 
but it seems they open at their minute extremities into mere vacuities 
in the ultimate parenchyma of the body. Thus the whole lymphatic 
system may be regarded as an enormously and most complexly 
ramifying body cavity, the ramifications of which have all acquired 
a lining membrane, save the most ultimate ones, from which ultimate 
terminations the lymphatic vessels, therefore, seem to take their 
origin. 

The various lymphatic vessels ultimately gather themselves 
together from all parts of the body into one or other of two 
longitudinal vessels, which are named the right and left lymphatic 
ducts, and which are very unequal in size. 

That of the right side receives only the lymphatics of the head 
and the fore-limb of its own side and from the same side of the 
chest. That of the left side receives not only the lymphatics of the 
head, arm and part of the chest of its own side, but also those 
of both the hinder limbs and all the lacteals. It is distinguished 
by a distinct name, the thoracic duct, but it and the right lymphatic 
duct, respectively open into the subclavian vein of its own side, just 
where it receives the accession of the jugular vein. 

The thoracic duct advances along the ventral side of the spinal 
column from a somewhat dilated part called the receptaculum chyli, 
which lies on the right side of and rather dor sally to the aorta. 
The duct passes forwards, inclining to the left, to the root of the 
neck, where it terminates, as before stated. 

Lymphatic glands. — There is a considerable cervical gland, about 
the size of a very small bean, just behind the external jugular vein 
at the level of the clavicle. 

Other lymphatic glands lie near the axilla, a group of three or 
four being covered by the latissimus dorsi muscle near its insertion. 
Others are situated more deeply in the axilla, itself. 

A few lymphatic glands lie in the thigh just beneath the skin 
at about half an inch from the pubic symphysis. 

Yet other lymphatic glands a*re to be found, besides various blood- 
vessels and viscera. 

A large gland lies at about the middle of the trachea on its ventral 
aspect, immediately beneath the sterno-thyroid muscle, and a smaller 
one lies more anteriorly and superiorly near the angle of the 
mandible. 

Certain lymphatic glands, placed in the mesentery, are known as 
mesenteric glands. The lacteals collect together and traverse them 
on their way to the larger lymphatic trunks. Most of the mesen- 
teric glands are aggregated together into an elongated mass, which 



chap, vii.] TEE CATS ORGANS OF CIRCULATION. 219 

is placed near the root of the mesentery, and which mass is often 
called the pancreas of Aselli. There are, however, five or six isolated 
glands of this kind in the vicinity of the large intestine. 

After passing through the mesenteric glands, the lymphatics 
converge, increase in size, and finally enter the thoracic duct 
towards its hinder end. 



CHAPTEK VIII. 



THE CAT S ORGANS OF RESPIRATION AND SECRETION. 



§ 1. The function of respiration is that one of all the func- 
tions of the body which is the most conspicuously necessary for the 
maintenance of life. Let this function be interrupted in the adult 
cat* but for ten minutes (whether by external obstruction, the 
absence of the requisite gaseous material, or by paralysis of the 
respiratory organs), and death is the necessary result. It has been 
already mentioned in the chapter on Alimentation, that oxygen is 
taken into the body through the lungs ; and it has also been 
stated — in the last chapter — that the blood undergoes a conspicuous 
change (from its purple venous state to its scarlet arterial condition) 
during the pulmonary circulation. This change is due to the 
absorption by the blood, and consequent increase of its supply, of 
oxygen, and to the elimination from the blood of more or less of its 
carbonic acid. 

It is this interchange of gases between the living animal and the 
surrounding air which constitutes " breathing," or respiration. But 
the animal we are considering may be said to have two processes of 
respiration — one " internal/' the other relatively " external." Such 
is the case, because the oxygen received into the blood does not 
remain there, but is carried by the circulation to the remotest 
recesses of the body, where it unites with that body in its innermost 
substance or parenchyma. 

Similarly, the carbonic acid which the blood sets free does not 
originate in the blood, but is given forth into the blood from all the 
ultimate particles of the same parenchyma. 

Thence, the blood gathers it, and conveys it outwards for dis- 
charge in the lungs. The blood, therefore, is a great distributor, 
which both gives out and takes in oxygen and carbonic acid at 
either end of its course, from the lungs to the innermost body 
substance. 

In the lungs it gives out carbonic acid, and takes in oxygen (as 
has just been said) ; while in the inmost recesses of the body it 



* In the chapter on Development it 
will be explained how it is that inter- 
ruption in the process of respiration is 



not so rapidly fatal in the kitten as it is 
in the adult cat. 



chap. Yin.] ORGANS OF RESPIRATION AND SECRETION. 221 

gives out oxygen and takes in carbonic acid. Internal respiration, 
therefore, is the absorption of oxygen and the elimination of carbonic 
acid by the ultimate parenchyma of the body's substance, which is 
bathed by the nutritious oxygenated fluid as it exudes from the 
capillary vessels. External respiration is the absorption of oxygen, 
and the elimination of carbonic acid by the blood, on what is 
essentially the surface of the body ; for the lining of the lungs is but, 
as it were, a very deep and complex inbending and infolding of the 
body's external surface, as has been already pointed out in the 
second chapter. The oxygen thus received in the lungs, appears in 
part to form an actual chemical union with the matter of the red 
corpuscles, and in part to be dissolved in the liquor sanguinis. The 
elimination of carbonic acid, it is maintained, is produced by an 
actual process of chemical decomposition. 

It is necessary that the air respired be more or less fresh, and it 
cannot be used over and over again an indefinite number of times ; 
for all that some oxygen still remains within it. 

Ordinary atmospheric air contains nearly 7,900 parts of nitrogen 
and 2,100 of oxygen, with a small quantity (3 parts in 10,000) of 
carbonic acid. 

The air expired, however, has about 470 parts of carbonic acid, 
and less than 1,600 parts of oxygen — the quantity of nitrogen 
remaining about the same as in fresh air. Thus about 5 per cent. 
of oxygen is gained, and 5 per cent, of carbonic acid is lost in the 
process of respiration. These changes correspond with changes in 
the blood. Thus, in 100 parts of venous blood there may be five 
parts of oxygen and twenty-five of carbonic acid, while in the same 
quantity of arterial blood there may be ten parts of oxygen and 
twenty of' carbonic acid. 

However rich in oxygen the air inspired may be, no more oxygen 
is absorbed than the processes of life demand. The organism 
regulates itself in this respect. The more the blood is charged with 
carbonic acid, the greater is the quantity given off in the lungs. 

If, instead of nitrogen, hydrogen or marsh gas be mixed with 
oxygen in due proportion, and breathed, the compound can be 
respired for an indefinite time. Some gases, however (such as 
hydrochloric acid, sulphurous acid, ammonia, chlorine, fluorine, and 
others), cannot be respired, because their action is so irritating to 
the breathing organs that the entrance to the windpipe becomes 
involuntarily closed against them. 

Other gases can be respired, but are poisonous if they are 
respired. Such are sulphuretted hydrogen, phosphuretted hydrogen, 
nitric oxide, carbonic oxide, and some others. 

If pure oxygen be respired, it removes the carbonic acid from the 
blood too rapidly, so that the blood thereby ceases to possess a 
necessary element for effecting the respiratory changes. The result 
of this is death by what is called apncea. Death produced by 
absence of oxygen, is called asphyxia. 

The gaseous interchanges which take place in the lungs, are not 



222 THE CAT. [chap. viii. 

effected immediately by the fresh air last taken in, but only by it 
after it has become diffused (according to the laws of gaseous 
diffusion) through the stationary air previously respired. It is 
effected by this stationary air because, as we shall shortly see, only 
a small part of the air which the lungs contain, is introduced or 
expelled at each respiratory movement. This stationary air is then 
the direct agent in effecting the exchange, and it is on this account 
that the air last expelled in each act of expiration, is the part most 
loaded with carbonic acid. Thus both external and internal 
respiration are processes which go on continuously, and without 
any such intermissions as those which take place in that alternating 
action which popularly goes by the name of " breathing,' ' but 
which is merely a process of introducing into the body that material 
by which respiration, or true " breathing, " can be effected. 

§ 2. The process of respiration in the cat is something more than 
this mere interchange of gases, since whatever be the dryness of 
the air inspired, the air given forth in its breathing is nearly 
saturated with moisture, so that much water is thus given out from 
the body daily. Moreover, however cold may be the air taken into 
the body in breathing, the animal's breath as it is given forth is 
always hot, having become heated by the internal heat of the body. 
This heat is due to a process of chemical change taking place, as 
lately mentioned, in the innermost parenchyma of the body. Now, 
wherever chemical combination takes place, heat is evolved, and 
therefore those intimate processes of life which are effected by 
internal respiration have been described as a sort of slow combustion. 
External respiration then is the indirect cause of the heat of the 
cat's body, as may be shown by the increase of heat produced in it, 
by increased rapidity of breathing. Nevertheless, that it is only an 
indirect cause, is proved by the fact that the body may not only 
continue warm for some time after death, but that, under special 
circumstances, its temperature may temporarily increase. 

This process of heat generation can go on as long as food is 
supplied, and the temperature of the body can be maintained at an 
even heat of about 100° Fahr., in spite of a very low external 
temperature in the winter season. The animal thus being always 
" warm-blooded." 

By these chemical changes in the recesses of the tissues, not only 
is nutrition effected, but also the waste products of the wear and 
tear of life are removed by the introduced oxygen decomposing those 
products and converting them into soluble crystalloids or into gases 
— changes which enable them either to pass out readily at the lungs, 
or else through the skin or through organs hereafter to be described, 
namely the kidneys. 

The function of respiration as generally understood, i.e., external 
respiration, is effected by a certain set of organs, which form two 
categories. The first category includes the accessory organs of 
respiration, or parts which convey air into the body, and which again 
expel it when it has done its work. The organs of the second 



chap, viii.] ORGANS OF RESPIRATION AND SECRETION. 223 

category, or the essentia! respiratory organs, are those which place 
the blood in intimate relation with the inspired air. To the first 
category belong the windpipe, and the grosser structure of the 
lungs, with the muscles and other parts which aid in drawing air 
inwards and in again expelling it. To the second category belong 
the minute cells which form the ultimate and essential parts of the 
lungs — the " air-cells " or " alveoli. " 

In the cat there is but one real set of respiratory organs ; a 
certain respiratory action can indeed be also effected by the skin, 
but its amount is so minute it may be practically disregarded. 
Water ordinarily contains atmospheric air mixed up with it, but 
the cat has no organs by which the air thus contained can be 
respired, either by the external skin or by the lungs : for if water be 
introduced into the latter its introduction causes death, as also does 
the continued immersion of the whole skin in water. Nevertheless, 
as we shall see, the actual respiratory surface — the inner surface of 
the lungs — is always moist, and bathed with a thin watery film. 

§ 3. The tube by which air is introduced into the cat's body is 
the windpipe, or trachea, which is relatively very capacious, and 
opens anteriorly in the back of the floor of the mouth, while pos- 
teriorly it divides into two branches, each of which is called a 
bronchus, and penetrates into one of the two lungs. At its front end 
the trachea expands into a membranous and cartilaginous box-like 
structure called the larynx, and it is the larynx which opens into 
the mouth behind the root of the tongue. The trachea passes 
downwards and backwards down the neck and along the thorax on 
the ventral side of the oesophagus. It remains permanently hollow, 
like an artery, its cavity being kept open by means of a series of 
incomplete cartilaginous rings which surround the windpipe in 
front and at the sides, but do not extend into its dorsal wall (ad- 
joining the oesophagus), which is soft. The ventral surface of its 
hinder half is in contact with this thymus gland. 

Its lower end lies above the sternum and the arch of the aorta. 
Above the pulmonary artery, the trachea divides into the two 
bronchi. The right bronchus is short, and passes horizontally into 
the root of the right lung. The left bronchus is somewhat the 
longer, and passes to the left lung behind the arch of the aorta. 
Within the lung the bronchi divide and subdivide, like the branches, 
branchlets, and twigs of a tree. 

The cartilages of the trachea are forty -five in number, and are 
held in juxtaposition by fibrous membrane which embeds them. 
The highest cartilage is connected with and underlies the larynx. 
The soft layer which completes the trachea above, where the carti- 
laginous rings are incomplete, contains organic muscular fibres, 
internal to which is a stratum of elastic fibres which extend thence 
all round within the cartilages. More internally the tube is lined 
with mucous membrane, covered on its surface by a columnar and 
ciliated epithelium. 

The bronchi have the same structure as the trachea, except that 



224 TEE CAT. [chap. viii. 

their cartilaginous rings are shorter and narrower. The smaller 
tubes, into which the bronchi subdivide within the lungs, &re called 
bronchia. 

§ 4. The lungs (Fig. 89 and 112) are two in number, and are 
placed one on each side of the heart in the thorax. Together with 
the heart they fill up the main part of the whole thoracic cavity. 
They are attached each by a small part of its inner surface (called 
its root) to one of the two bronchi and to the great vessels con- 
necting that lung with the heart — the blood-vessels and air-tubes 
entering or leaving the lung, passing through one or other of its 
"roots. 1 ' From this attachment each lung hangs freely suspended, 
being conical in shape, with a broad, concave base, which is applied 
to the front surface of the diaphragm. Each lung is enclosed in a 
serous, shut sac, called a pleura, and the two pleurae together may 
be said to form the proper serous sac of the thorax, though each is 
quite distinct from the other. 

The two pleurae line the right and left halves of the thorax, and 
are reflected over the two lungs at their roots respectively. In this 
way the two adjacent (inner) sides of the two pleurae traverse the 
thorax from above downwards.. They are not, however, in contact, 
but separated by two interspaces termed mediastina. 

The anterior mediastinum contains the heart in its pericardium. 

The posterior mediastinum contains the oesophagus, the aorta, the 
vena azygos, and the thoracic duct, together with the two nerves 
called pneumogastric. 

Each lung is divided by fissures into lobes as follows : 

The left lung is divided by a deep fissure in two large and 
distinct lobes sub-equal in size (Fig. 104, 5 and 6 ). A less deep 
fissure also separates off a small lower portion ( 5 a) of the upper of 
the two lobes of the left lung. The right lung is divided by three 
deep fissures into four unequal and distinct lobes, the uppermost of 
these (Fig. 104, J ) is large and triangular. The next ( 2 ) is narrow 
and elongated, but much smaller. The third lobe ( 3 ) is the largest 
of all, and has on its inner side the fourth lobe, which is incompletely 
divided by a fissure into a larger external part ( 4 ) and a much 
smaller internal portion (%), both of which are narrow and pointed at 
the end. 

As to their minute structure, the lungs consist of a prodigious 
number of small air-bags, called " lobules," attached to the finer 
ramifications of the bronchi. These lobules are united together by 
connective tissue with blood-vessels and muscular and elastic fibres, 
and can very plainly be discerned at the surface of the lung. The 
lungs may therefore be described as spongy and highly elastic 
organs which (when once respiration has taken place) will float if 
thrown into water, and which, if artifically inflated after removal 
from the body, will spontaneously contract and expel the air so 
introduced, through the elastic nature of their substance. 

The smallest bronchial ramifications cease to be lined with ciliated 
epithelium, and have squamous epithelium instead. 



chap, vin.] ORGANS OF RESPIRATION AJW SECRETION, 225 

Each, bronchial tube, while still cylindrical, enters one of the 
lobules and there ramifies, its ramifications ultimately dilating into 
a larger passage called an infundibulum, the walls of which are 
beset with numerous little sac-like dilatations, called air-cells, alveoli, 
or pulmonary vesicles. These are naturally filled with air, and their 
membranous walls are strengthened with elastic and some muscular 
fibres, and beset with a multitude of delicate capillary vessels, which 
expose the blood they contain to the action of the air in the alveoli. 
The arteries (carrying the venous blood for oxygenation) end in 
minute twigs, which surround the margins of the alveoli, whence 
the capillary vessels extend inwards, and are subjected to the air on 
both sides of the moist, delicate m embrane in which they ramify. 
The minute veins which issue from the capillaries, and which carry 
arterial blood, do not run side by side with the arteries, but, pur- 
suing a different course, frequently anastomose and increase in size 
till they end in the great pulmonary veins, which proceed through 
the roots of the lungs to the left auricle, as before described. 

Besides the pulmonary arteries (which bring blood for respiration), 
the lungs have their own proper arteries and veins, which are 
concerned in their nutrition. These, are the bronchial arteries and 
veins, and they are smaller than the other blood-vessels of the lungs — 
the pulmonary arteries and veins. 

The bronchial arteries are derived from the aorta, and follow the 
divisions of the bronchi within the lung. The bronchial veins unite 
together to pass out at the roots of the lungs. 

§ 5. The mechanism of respiration has already been slightly 
noticed, in the fifth chapter, in relation to the action of the 
diaphragm and intercostal muscles, which serve, by their alternate 
contraction and dilatation, to modify the capacity of the thorax. 
The serrati postici muscles, by drawing backwards the ribs to which 
the diaphragm is attached (at the very time that the other ribs are 
being drawn forwards, and the diaphragm, by its contraction, 
rendered less convex) aid in temporarily enlarging the thoracic 
cavity, and so causing an influx of air into the lungs. In this action 
the serrati antici and scaleni also give aid by drawing the anterior 
ribs forwards. 

The pumping action of the diaphragm is the main agent in 
respiration, the relaxation of its fibres allowing it to become convex 
anteriorly, and so encroach upon the thoracic cavity — air being 
necessarily driven out of the lungs thereby. But the expulsion of 
air in expiration is largely due to the highly-elastic nature of the 
pulmonary structures (which has been already pointed out),* and to 
the muscular contraction of the bronchi. The abdominal muscles 
however are also called into play to effect a forcible expiration. 



* It is owing to this elasticity that if 
a perforation he made in the wall of the 
thorax, the lungs will contract greatly. 
For by such injury the atmospheric pres- 
sure within, becomes neutralized by 



atmospheric pressure on their outer sur- 
face ; from which pressure, the un- 
injured thoracic wall before protected 
them. 



226 THE CAT. [chap. viii. 

The alternation of acts of inspiration and expiration (one of the 
former commencing the series at birth, and one of the latter 
terminating it at death) goes on unceasingly, but at a rate which 
varies according to circumstances — being most frequent during 
violent exertion. 

What is called the inspiratory rythn consists of three parts: 
(1) the act of inspiration ; (2) that of expiration, which endures 
but little more than half as long as the former ; and (3) an interval 
of rest, which is much shorter than either. 

Inspiration aids the circulation indirectly by pressing on the great 
vessels, the difference between the strength of the walls of the 
arteries and veins causing the pressure to be no impediment to the 
former, while the same pressure aids the How of the blood in the 
latter. 

Applications of the respiratory actions produce a number 
of familiar actions, such as yawning, which is a prolonged inspira- 
tion ; coughing and sneezing, which are sudden acts of expiration, 
the former being preceded by a prolonged inspiration — the air 
passing out by the mouth. In the latter it passes out only through 
the nose. All forms of mewing, howling, and other vocal manifesta- 
tions, are modified expiratory actions. 

The term vital capacity refers to the capacity of the lungs as 
estimated by the greatest quantity of air which can be expelled 
from the lungs by the most forcible expiration after they have been 
inflated by the deepest inspiration. But no expiration, however 
violent or prolonged, will, nearly expel the air which the lungs can 
be made to contain — while in ordinary respiration but a very small 
part ebbs and flows. 

This small quantity is called the breathing or tidal air. That 
which always remains and can never be expelled is called the 
residual air ; that which ordinarily remains in the lungs after 
expiration, but which can be expelled, is called the reserve or sup- 
plemental air, and that which can be drawn in by a prolonged 
inspiration, beyond that ordinarily so taken, is termed the com- 
plemental air. These phenomena have been accurately observed 
only in man, but the essential conditions are the same in the cat. 

§ 6. It has just been said that all vocal manifestations are 
modified expiratory actions ; but these actions, in order that they 
should produce sounds, need the aid of a peculiar mechanism. This 
mechanism is furnished by that expanded, anterior end of the 
windpipe which has been already referred to as the larynx. 

To the upper, anterior margin of the larynx, the hyoid bone is 
attached, and therefore also the tongue, behind the root of which is 
the laryngeal opening into the pharynx— the "glottis" — already 
spoken of as situated in front of the oesophageal opening, and as being 
protected by that cartilaginous process the epiglottis, which stands 
up in front of it. The larynx is formed of three large and two small 
cartilages, united together by fibrous tissue moved by muscles, and 
supplied with blood- vessels, lymphatics, and nerves, the whole structure 



chap, viii.] ORGANS OF RESPIRATION AND SECRETION. 227 



being lined with mucous membrane, which is supplied with numerous 
mucous glands. Amongst the parts formed of fibrous tissue are 
two internal ligaments on each side of its cavity, called the vocal 
cords, which are the immediate agents in the production of the 
voice. The whole of the inside of the larynx below these cords 
is coated with ciliated epithelium, and also for a short distance 
above them. The action of the cilia is to 
propel the mucous secretion towards the 
upper aperture of the larynx. 

Of the CARTILAGES OF THE LARYNX, 

three are median, azygos structures, and 
the others are arranged as a pair. 

The largest of the three median struc- 
tures is called the thyroid cartilage, which 
consists of two lateral parts {alee) united 
at an acute angle or sharp curve, opening 
backwards — i.e.. dorsally. Each ala is 
somewhat quadrilateral (an elongated paral- 
lelogram) with its anterior (ventral) border 
(where it joins its fellow of the opposite 
side) the shortest, while its posterior border 
is prolonged upwards and a little down- 
wards, into two rather blunt processes 
termed cornua. The two posterior borders 
are nearly vertical, with an undulating 
margin, and are widely separated from 
one another. The inferior margin of each 
ala is concave in front of the inferior 
cornu, while more anteriorly it is slightly 
convex, and then concave, so that there is 
a slight median notch at the under border 
of the thyroid. The superior margin of 
each ala is also concave in front of the 
superior cornu, while more anteriorly it is 
strongly convex, there being no notch at 
the point where the upper margins of 
the two alae meet together in front. Each 
ala is smooth and rather concave within, 
from .above downwards. The superior 
cornua are connected by a ligament called 

the thyro-hyoid ligament, with the tip of the thyro-hyal of the 
same side. They are also closely connected, through the medium 
of the thyro- and cerato-hyals, with the stylo-hyals. Each inferior 
cornu articulates with the outside of the cartilage to be next de- 
scribed. It is much shorter than the superior cornu. 

The cricoid cartilage is ring-shaped, and may be considered as the 
modified, topmost cartilage of the trachea. Greatly modified it 
certainly is, since, instead of being defective behind, as are the 
tracheal cartilages, and as is the thyroid cartilage, it is much larger, 

q 2 




Pig. 106.— View of the "Right 
Side of the Cartilages of the 
Cat's Larynx —seen more or 
less separated. 

The uppermost is the epiglottis 
(e). 

th. Is the thyroid, and (c) is its 
superior cornu. The small 
cartilage below is one of the 
arytenoids, with an articular 
surface for the cricoid (a), and 
with a small process (cl) at 
its summit. 

Beneath is the cricoid (cr , with 
the articular surface for the 
arytenoid indicated imme- 
diately beneath the repre- 
sentation of that small carti- 
lage. 

1 , 2 , 3 , and 4 , are the four upper- 
most rings of the trachea- 



228 



THE CAT. 



[CHAP. VIII. 



and more developed behind than elsewhere. Its lower border is 
slightly undulating, and is connected by membrane with the upper- 
most cartilage of the trachea. Its convex upper posterior border 
has a scarcely perceptible median notch, and on each side of this is 
an oval, convex, articular facet. Internally this cartilage is lined by 
the mucous membrane of the larynx. 

The third median cartilage is the epiglottis, which is acutel} 
pointed above and very obtusely so below, where it is attached by 
ligament to the inside of the thyroid. The posterior (dorsal) surface 
of the epiglottis is concave from side to side. Vertically, its anterior 
(ventral) aspect is concave above and convex below (Fig. 106). It 
is invested with mucous membrane both in front and behind, except 





Fig. 107.— The Larynx and Glottis of the Cat. 



A. Aperture of the glottis contracted. 

B. The same dilated. 

C Opening into the larynx. 

a. Arytenoid cartilages. 

ac. False vocal cords. 

e. Epiglottis. 

fv. Crico-epiglottic ligaxents. 

v. True vocal cords. 



D. Vertical section through the trachea and 

oesophagus. 
a, ac, e, and fv, as in figure C 
Between ac and v is the ventricle of the 

larynx, 
cr. Cricoid cartilage cut through. 
ce. Oesophagus. 
t. Trachea. 



the lower part of its front surface, where it is attached to the tongue 
and hyoid by ligaments — that which connects it with the hyoid being 
elastic. It is connected on each side by a strong fold with (Fig. 
107, fv) the side of the cricoid cartilage close to the base of the 
arytenoid cartilages. 

The two arytenoid cartilages rest each on one of the two oval 
articular surfaces before mentioned as situated one on each side of 
the median posterior notch, in the upper border of the cricoid 
cartilage. Each arytenoid cartilage is irregularly pyramidal in 
shape, the base of each pyramid resting on the cricoid. The summits 
of the arytenoid cartilages curve somewhat towards each other. 

A good many ligaments connect the different portions of the 
larynx. Thus there is the thyro- epiglottic and hyo-epiglottic con- 
necting the epiglottis with the thyroid and os hyoides respectively. 



chap. Tin.] ORGANS OF RESPIRATION AND SECRETION. 229 

The aryteno- epiglottic, which might be called " crico- epiglottic," is a 
thick fold of membrane (Fig. 107, jv) which proceeds from the base 
of the outside of each arytenoid and contiguous part of the cricoid, to 
the side of the epiglottis. The thyro-hyoid connects the os hyoides 
with the thyroid, while the cnco-thyroid connects the latter with the 
cricoid, filling up the interval between them and containing much 
elastic tissue. 

The most important ligaments, however, are these called the 
" vocal cords," of which there are two kinds on either side of the 
cavity of the larynx. The superior or false vocal cords — called also 
the superior thyro-arytenoid ligaments — are folds of membrane which 
pass (one on each side) from the anterior aspect of the arytenoid 
cartilages downwards and forwards to the mucous membrane of the 
middle of the posterior (dorsal) surface of the epiglottis and thyroid 
(Fig. 107, ac). These are very prominent folds of membrane, and it 
is by their vibrations that the sound of " purring " is said to be 
produced. 

The inferior or true vocal cords — called also the inferior t/tyro- 
arytenoid ligaments — have a similar but lower origin and insertion 
to the false vocal cords (Fig. 107, v) ; they are less prominent and 
sharply edged. It is these true vocal cords which by their vibra- 
tions are said to produce the mewing and howling sounds. These 
cords leave between them an aperture termed the rima glottidis, and 
they tend to form a horizontal partition dividing the cavity of the 
larynx into an upper (anterior) and a lower (posterior) portion. 
The whole larynx opens into the pharynx by its superior aperture — 
the glottis — which is bounded in front by the epiglottis, behind by the 
arytenoid cartilages, and on each side by the aryteno-epiglottidean 
folds, and by the false vocal cords. Between the false and true vocal 
cords of each side is a small depression called a " ventricle." These 
two depressions, however, are so slight as hardly to deserve notice. 

§ 7. The voice is produced by the vibration of the edges of the 
vocal cords (when stretched and approximated), which vibration is 
effected through the passage outwards of a stream of air, according 
to the laws which regulate the vibrations of strings and membranes 
Accordingly, certain muscles act upon the arytenoid cartilages, and 
by their action put the membranes on the stretch, and so alter 
the shape of the opening of the glottis by contracting it (Fig. 107, 
A & B). The more the cords are stretched, and the narrower the 
aperture, the shriller are the sounds emitted. 

Though the vocal cords are the main agents in the production of 
sounds, the tone and qualities of these sounds are modified by shape 
of the cavities of the larynx, pharynx, and even of the air-cavities of 
the skull, and by the physical qualities of all these parts. To effect the 
needful changes, appropriate motor agents are needed, and there 
are no less than eight pairs of laryngeal muscles. The crico-thyroid 
muscles extend from the upper border of the cricoid to the outside 
of the thyroid and its lower cornua. Their action is to rotate the 
thyroid downwards and to stretch the vocal cords. Two pairs of 



230 THE CAT. [chap. viii. 

muscles — posterior and lateral crico-arytenoids — pass from the cricoid 
to different parts of the arytenoids, which the former rotate out- 
wards, and the latter inwards, thus either widening or contracting 
the glottis. The thy ro-ary toxoids and the artyeno-epiglotUdean muscles 
have the same connexions as the true vocal cords and the aryteno- 
epiglottic ligaments respectively. The glosso-epiglottidean muscles 
pass from the back of the tongue downwards to the base of the 
front of the epiglottis, and 1he hyo-epiglottidean muscles are very 
small ones, extending from the hinder surface of the basi-hyal, down 
to nearly the same part of the epiglottis as that into which the last- 
mentioned muscles are inserted. 

Lastly, the arytenoid muscles connect and tend to approximate the 
two arytenoid cartilages. 

§ 8. In treating of respiration and the respiratory organs, we have 
mainly been occupied with that which ministers to the nutrition and 
warmth of the body by enabling it to obtain its due supply of oxygen. 
We have, however, also noted that the process of respiration is in part 
a process of elimination and removal from the body of a portion of the 
waste products of its vital activities. This now requires more careful 
consideration. Life is a series of compositions and decompositions, 
and in order that assimilation may go on, a process of disassimilation 
must necessarily accompany it. With the addition of new and unused 
material, there must go on a subtraction of old and effete material, and 
this (as we have lately seen) is mainly brought about by a process of 
oxydation in the inmost parenchyma of the body. We have seen, 
in studying alimentation, that colloids have to be changed into 
crystalloids, that they may be conveyed to the colloidal parenchyma, 
into which they have to be transformed. Similarly in the process of 
disassimilation. the effete colloidal parenchyma has to be reconverted 
into crystalloids that it may be conveyed away and excreted, though 
the crystalloids of excretion are generally different from those of 
nutrition. 

It has also already been pointed out that the digestion of the 
food is aided by the juices of the salivary glands and pancreas, and 
other similar structures. Now these juices do not exist as such in 
the blood, but are formed from it by a mysterious power which 
certain cells possess thus to form new products. The exercise 
of this power is called " secretion" and it is a power analogous 
to that by which the various tissues are enabled to add to their 
own substance from the life-stream which bathes them, though 
their substance does not exist, as such, in that stream. Thus 
" assimilation " is a sort of " secretion. " Nevertheless it cannot be 
said that " secretion " is a sort of " assimilation." " Assimilation " it 
a process of forming products and adding them to the body ; bus 
" secretion" is a process of forming products which are to be got rid 
of, or are destined to aid in other life processes. Thus secretion is a 
special function, and as such has a special organ — a gland. Glands, 
as we have already seen, are either simple or complex involutions 
of an epithelial surface. We have seen simple ones in the sweat 



chap, viii.] ORGANS OF RESPIRATION AND SECRETION. 231 

and mucous glands, and complex ones in the salivary glands, the 
pancreas, and above all, the liver. The foldings or subdivisions of 
a gland are manifestly but a convenient mode of augmenting the 
secreting surface within a small space. Since all secretions are 





Fig. 108.— Diagram of different forms of Glands, showing how the Secreting Surface 
may be augmented, and the glandular structure rendered si ore complex by 
Inversion or Recession of the Surface to a greater and greater degree. 



A. Simple glands. 

g. Straight tube. 

h. Sac. 

i. Coiled tube. 

B. Slightly more complex forms. 

k. Tubular. 
I. Saccular. 

C. Racemose or compound saccular gland 



m. The entire gland, showing its branching 

duct and lobular structure. 
7i. A separated lobule, with one branch of 
the duct (o) proceeding from it. 
D. Compound tubular gland. 
Secreting surfaces may also be increased by 
projections and foldings outwards, analogous 
to these inversions and foldings inwards. 



formed from the blood, every secreting surface, and therefore every 
gland, must be highly vascular. It is as yet quite unknown what 
causes different epithelial cells to have the power of forming such 



232 



THE CAT. 



[CHAP. VIII. 



different secretions as are those, for example, of the sweat glands, 
salivary glands, synovial membrane, and liver. The undivided tube 
of a gland by which its secretion is poured out is its duct. The se- 
cretions, and therefore their glands may, as we have seen, simply 
serve to aid the process of assimilation. They may also aid the 
function of generation, or, finally, they may merely serve for ex- 
cretion, i. e. y to get rid of waste products or excreta. Certain large 
and small glands have already been described in the sixth chapter, 
namely, the liver, the pancreas and the various salivary glands. 
The anal glands were also therein noticed. It remains to describe 
those very important glands, the kidneys. 

§ 9. As the foods and the tissues of the body may both be 
divided into nitrogenous and non- nitrogenous substances, so also 
the excreta of the body may be similarly divided. The non- 





"iPig. 109. -The Cat's Kidney, entire and in section. 



A. The outer surface of the kidney, showing the 

network of blood-vessels. 
a. Renal artery. 
v. Ureter. 
v. Renal vein. 

B. Vertical section through the kidney. 

c. Cortical substance. 



i. Expanded end o? the calix surrounding 

the mammilla, 
o. Dark spots in cortical substance. 
p. Papilla, or mammilla. 
pi. Pelvis. 
t. Tubules of the kidney. 



nitrogenous products of waste are eliminated by the lungs, and to a 
very much less degree by the skin in the form of water and carbonic 
acid. But a very large portion of the waste products are nitrogenous. 
These are eliminated in a trifling degree also by the skin, but the 
special organs for their elimination are the renai organs or kidneys. 
A process of oxidation in the innermost substance of the body 
converts the nitrogenous waste matter into urea, uric acid, ammonia, 
and certain other acids and salts which are crystalloidal derivations 
from colloidal tissues. The kidneys extract all these, with much 
water, from the blood, and so form urine. 

§ 10. The kidneys differ from the lungs in that they are organs 
of excretion only. The lungs excrete, but as we have just seen, they 
also take in. The secretion of the kidney, the urine, passes down 
from those organs by two tubes into a receptacle — the bladder — where 
it accumulates, and whence it is expelled at intervals. 

The kidneys are two organs placed one on either side of the 



chap, vhi.] ORGANS OF MESPZRATION AJSfD SECBETION. 233 

vertebral column, a little behind the attachment of the diaphragm 
(Fig. 105) They lie against the dorsal wall of the abdominal 
cavity above (i.e., the dorsal side of) its peritoneal lining. The 
anterior end of the right kidney adjoins the posterior surface of the 
livsr. The left kidney is in proximity to the spleen. 

Each kidney is a rounded body, smooth externally, and showing 
superficially an arborescent network of veins (Fig. 109, a.) It is 
convex everywhere, except on its inner side, where it presents a 
marked concavity. From the middle of this concavity a tube, called 
the ureter, proceeds inwards and backwards to the bladder (Fig. 10b,u). 
This tube is the duct of the renal gland, and it emerges from a 
fissure in the concave surface, called the hihis of the kidney. From 
this hilus the renal vein (Fig. 109, a, v) also issues, and into it the 
renal artery (a) and the nerves enter. The artery enters on the 
dorsal side of the emergence of the vein. 

As to its structure, the kidney consists of an immense multitude 
of minute tubes, with vessels, nerves, connective tissue and fat, all 
enclosed in a thin but firm fibrous coat, which closely invests the 
gland and contains elastic fibres. 

On making a longitudinal section of the kidney it is seen to be of 
a more or less red colour and to contain a heart-shaped cavity 
(Fig. 109, b, pi) towards its inner border. Its solid substance 
appears divisible into an external layer of a lighter tint, containing 
minute dark red spots (o) — the cortical substance — while the rest 
is darker coloured and forms what is termed the medullary 
substance. 

The cavity above referred to is the continuation inwards of that of 
the duct of the gland (the ureter), and is called the pelvis (pi). As 
the pelvis penetrates the gland it enlarges (i) and surrounds a 
central prominence w T hich projects into it. The part surrounding 
this prominence is called the calix. 

The cortical substance forms one continuous layer, and the 
medullary substance is also arranged in a conical mass or pyramid, 
the apex of which is directed inwards and projects into the calix as 
the mammilla or papilla (p), the tubes of which it is composed (t) 
converging to the mammilla. 

The pelvis is lined with mucous membrane, which is reflected 
over the apex of the mammilla. 

The minute tubes (t) of which the kidney is mainly composed are 
called tubuli uriniferi. They are very closely packed, and 
consist of a transparent membrane lined with a polygonal or a 
spheroidal and glandular epithelium occupying two- thirds of their 
diameter. These tubuli open on the surface of the mammilla, 
whence they pass into the substance of the kidney, dividing and 
subdividing, but continuing a nearly straight course till they como 
to the cortical layer, where they become much smaller in size and 
variously contorted in all directions, whilst they freely anastomose. 
Scattered about in the cortical substance are small capsules (the 
red specks already spoken of) or Malpighian corpuscles. These aro 



234 



THE CAT. 



[chap. VIII. 



the expanded terminations of the contorted uriniferous tubes. Each 
such corpuscle contains a hunch of minute looped capillary vessels, 
forming what is called a glomerulus (Fig. 110, /*), and has itself a 
most delicate epithelial lining contrasting with the thick spheroidal 
lining of the uriniferous tubes. A small artery enters each glome- 
rulus, and there breaks up into a number of minute branches ending 
in a capillary network, whence a small vein (Fig. Ill, e') arises, 




Fig. 110.— Semi-diagrammatic representation 
of a Malpighian Body in its relation 
to the Uriniferous Tube. Magnified 
300 diameters. 

a. Capsule of the Malpighian body continuous 
with (b), the membrana propria of the coiled 
uriniferous tube. 

c. Epithelium of the Malpighian body. 

d. Epithelium of the uriniferous tube. 

e. Detached epithelium. 
/. Afferent vessel. 

g. Efferent vessel. 

h. Convoluted vessels of the glomerulus. 




Fig. 111. — Diagram showing the relation 
of the Malpighian Body to the Urini- 
ferous Ducts and Blood-vessels. 

a. One of the arteries. 

a'. A branch passing to the glomerulus. 

c. Capsule of the Malpighian body. 

t. Uriniferous tubes. 

e', e'. Efferent vessels, which subdivide in the 
plexus (p), surrounding the tube, and finally 
terminate in the branch of the renal vein (c). 



which leaves the glomerulus, and breaks up into another network 
or plexus (Fig. Ill, p) of capillaries surrounding the tubules, 
whence arise other veins, which convey the blood ultimately to the 
renal vein. Thus we have in the kidney a multitude of minute 
special circulations, each of which is analogous to the portal system 
or that of the coronary vessels of the heart. 

The function of the kidney is, as has been said, to remove 
nitrogenous waste products and salts from the blood by the secretion 
and excretion of urine, and it thus supplements the action of the 
lungs by the removal of matters which escape the action of the 
pulmonary organs. The blood comes, as we have seen, to the 
kidneys direct from the abdominal aorta, and is therefore as pure 
as when it leaves the left ventricle. In circulating through the 
kidney it is still further purified, namely, from its nitrogenous waste 
matters, and it also loses more carbonic acid by the formation of 
urine, than it acquires by any wear and tear of the tissues of the 
gland. Thus the blood which leaves the kidney is at its maximum 



chap, viii.] OBGANS OF RESPIRATION AND SECRETION. 235 

of purity and oxygenation, and is as bright and scarlet as when it 
entered it. 

The watery substance of the urine appears to drain from the 
vessels of the glomerulus into the cavities of the Malpighian cor- 
puscles, and its more solid constituents to be secreted by the thick 
epithelium of the tubules. 

Some of the constituents of the urine — such as urea, uric acid, 
and a substance called kreatine — already exist in the blood which 
comes to the kidneys, and their elimination therefore is rather an 
excretion than a true secretion ; not but what it may be doubted 
whether any such a purely passive and physical process as a mere 
straining- off action, really takes place in the living organism at 
all.* 

The action of the kidney is constant, and small quantities of 
urine are continually passing from the mammilla of each kidney to 
the pelvis, and thence, down the ureters, into the bladder. 

§ 11. The ureters are, as has been already explained, two ducts 
or tubes which proceed one from the pelvis of each kidney. They 
lie on the dorsal side of the peritoneum, and proceed inwards and 
backwards to the bladder (Fig. 105), being connected by loose 
areolar tissue to the parts adjacent to them. 

They enter the wall of the bladder very obliquely, opening within 
it each by a narrow, slit-like aperture, the margins of which are 
somewhat thickened so as to have a valvular action and check the 
reflux of uiine from the bladder into the ureters. 

Each tube consists of a canal of mucous membrane, lined with 
epithelium ; the mucous tube being invested with organic muscular 
fibres, which are again invested externally by connective and elastic 
tissue. 

§ 12. The bladder (Figs. 105 b and 115), is a hollow, rounded 
vessel with three openings, two (those of the ureters,) by which the 
urine is received, and one (that of the urethra,) by which it is 
discharged. These three apertures define a triangular portion of the 
bladder called the trigone. 

The bladder is connected with the anterior wall of the abdomen, 
at the umbilicus, by a fibrous cord called the urachus, which is the 
remnant of a foetal structure, and at least occasionally includes 
a small irregular internal cavity lined with epithelium. 

The bladder is also attached to adjacent parts by folds of peri- 
toneum and of fascia. The inside of the bladder is lined with 
mucous membrane invested with squamous epithelium. The mucous 



* The pungent, and to most persons, 
disagreeable odour of the male cat is 
notorious. Yet it must be due to causes 
other than those which determine the 
essential function of renal secretion, since 
it is absent from the urine of the female 
cat, and also from that of the castrated 



male. The urine of all the species of the 
cat family has (as far as known) a more 
or less powerful and disagreeable smell, 
but its odorous qualities differ much in 
different species, as the author has been 
assured by Mr. A. D. Bartlett. 



236 



THE GAT 



[chap, vin. 



lining is loosely attached to the outer coats of the Madder and is 
therefore thrown into folds when the viscus is empty. . 

The outer coats of the bladder are muscular and fibrous. Its 
muscular coat is formed of organic fibres in several layers. Its 




Fig. 112.— Portion of the Neck and Thorax of a Kitten, dissected to display the 
large Thymus Gland. 



a. Right auricle of heart. 

ca. Carotid artery. 

I. Larynx. 

Ig. Lung. 

pn. Pneumogastric nerve. 



t. Trachea. 

tg. Thyroid gland. 

fy. Thymus gland. 

v. Ventricle. 

vca. Vena cava anterior. 



fibres are all so arranged as to remind us of figures of 8. They 
extend in almost every direction, and intersect each other on the 
front and hind surfaces of the bladder. Towards the orifice leading 



chap, viil] ORGANS OF RESPIRATION AND SECRETION. 237 

to the urethra the fibres assume a circular course, and so form a 
somewhat dense mass called the sphincter of the bladder. 

External to the muscular coat is the fibrous investment of the 
bladder. 

The passage by which the urine passes from the bladder to the 
exterior is named the urethra. 

The urine is expelled by contraction of the muscular coat and 
relaxation of the sphincter, and is aided by contraction of the 
abdominal muscles and diaphragm and by a small muscle called the 
accelerator urines (Fig. 115, 2 ). 

§ 13. The suprarenal capsules are two small roundish, somewhat 
flattened bodies (Fig. 105, sr), situated one in the vicinity of the inner 
part of the anterior end of each kidney, being attached there by 
areolar tissue. Each consists of an o^ter cortical part, of a firm 
consistency and yellow colour, and an inner softer and darker 
medullary portion. It has a fibrous investing membrane intimately 
connected with the cortical substance, which is made up of delicate 
filamentous tissue with interspaces filled with granular matter, 
nucleated cells and oil globules. These organs are richly supplied with 
nerves, but they have no duct, and their function is quite unknown. 

§ 14. The thyroid body or gland is another ductless structure of 
unknown function. It is very vascular, of a soft consistency and 
reddish colour, and lies (Fig. 112, tg) beside the trachea just below 
the larynx. It consists of two lateral parts, each of about the size 
of a small bean. There is no median connecting portion, so that 
there should rather be said to be two thyroid glands than one. It 
is composed of a number of minute, closed vesicles, which contain 
a yellowish, glairy fluid, and are connected by areolar tissue ; a thin 
but dense layer of which is the external investment. The thyroid 
body is supposed by some physiologists to regulate the supply of 
blood to the brain, and to prevent undue cerebral pressure by 
acting as a collateral blood reservoir. 

§ 15. The thymus is a structure which is of very large size during 
immaturity, but becomes smaller in the adult cat. Like the thyroid 
it is a ductless structure of unkuown function. It lies on the dorsal 
side of the sternum on the ventral aspect of the great vessels, and 
extends also far up the neck on the ventral surface of the trachea, 
as represented in Fig. 112. It is of a greyish or pinkish colour, and 
is soft and pulpy in consistency. It contains a central cavity, 
around which are arranged a number of lobes and lobules made up 
of delicate cells. A milky fluid is found within it, containing many 
nuclei and small nucleated cells. 

§ 16. Other ductless glands are the closed follicles which make 
up the " Peyer's patches," and " solitary glands " of similar nature 
have been already mentioned as being found in the intestine. An- 
other very small structure of a similar nature is called the " pitui- 
tary body." It will be hereafter noticed in describing the brain, to 
the under surface of which it is attached, lying within the sella 
turcica or the dorsum of the basi-sphenoid bone (Fig. 128). Yet 



238 



THE CAT. 



[CHAP. VIII. 



other ductless glands are the various lymphatic glands already- 
spoken of in the last chapter. 

§ 17. Another viscus, and one of large size, is akin in nature to 
the lymphatic glands. This is a large ductless organ already men- 
tioned as lying in the abdomen in the vicinity of the pancreas, close 
to the left side of the stomach. It is called the spleen. It is some- 
what variable as to shape and size, generally in the form of an 
elongated triangle, somewhat bent on itself, of a dark bluish colour, 
lying immediately behind the diaphragm. It is convex and smooth 
on its left side and concave on the side which is applied to the 
stomach, which is marked by a vertical fissure, called the Mlus, 
where the vessels and nerves pass into and out from its substance. 

Besides the peritoneum, the spleen is invested with a fibrous and 
very elastic coat which, at the hilus, is reflected into the body of 
the viscus, forming sheaths and canals for the large blood-vessels 




st. Wall of stomach 



Fig. 113.— The Spleen. 

py. Pyloric portion of stomach 



and nerves which ramify within it. Thus is formed a highly dis- 
tensible framework composed of areolar tissue, with a large quantity 
of elastic fibres. Amongst these elastic structures, with their 
vessels, is the red pulpy substance of the spleen. This is formed of 
nucleated and non-nucleated granular bodies, amongst which are 
scattered numerous whitish vesicles, called Malpighian corpuscles of the 
spleen, attached like buds to the sides of the minute branches of the 
arteries, and each composed of a fibrous bag enclosing granular 
nucleated corpuscles. 

The function of the spleen is so far related to alimentation that 
the organ begins to dilate while digestion progresses, reaching its 
largest dimension after a meal ; while later, if no fresh food be 
taken, it becomes reduced to its smallest size. A very remarkable 
fact, however, about the spleen is that it can be entirely extirpated 
without its loss producing any strikingly injurious effect. The 
function usually attributed to it is that of helping to replenish the 
nutritious fluid by forming lymph cells, which pass from it directly 
into the blood. Much obscurity, however, still remains as to the 
entire part it plays in the activities of life, and as to what may be 
really its main function. 



cilap. vin.J ORGANS OF RESPIRATION AND SECRETION. 



239 



§ 18. We have hitherto considered various organs which could 
be classed as alimentary or secreting organs, and some (like the 
pancreas, &c.) which were both, 
alimentary and secreting struc- 
tures, since they secreted a fluid 
destined to assist in alimenta- 
tion. Such secretions, however, 
were always destined for the 
service of the secreting or- 
ganism itself, and to help its 
own alimentary processes. But 
we have now to consider organs 
which are indeed both secre- 
ting and alimentary, but which 
secrete an aliment for the use 
of another organism than that 
which forms it. These are the 
mammary glands, or breasts, 
which secrete the milk destined 
to nourish the young. Hitherto 
we have met with a variety 
of organs, but only with organs 
which are pretty equally de- 
veloped in every individual 
cat. The mammary glands, 
however, are parts which, attain 
a large size and perform an 
important function, only in one 
set of individuals of the species 
we are occupied with — namely, 
in female individuals. These 
glands form a considerable 
mass, extending on each side 
of the ventral surface of the 
body, from near the axilla to 
the hinder end of the abdomen. 
Each gland is invested by 

fibrous tissue, which sends in septa (between the various parts of the 
secreting glands), accompanied by much adipose tissue. The ultimate 
structure of each gland consists of minute secreting cells bound up 
by connective tissue into little " glandules," each giving out a small 
duct, which, originates from the cellules and then joins with others 
to give rise to larger milk tubes, which ultimately end in certain 
conical dilatations or " reservoirs," from which very small excretory 
ducts extend forwards to a prominence or nipple, where they open 
by minute apertures. 

The excretory ducts are formed of connective and elastic tissue, 
with, an epithelial lining of small columnar cells. 

Each nipple is highly vascular, and contains organic muscular 
fibres, and its surface is beset with sensitive papillae. There are 




Fig. 114.— Cat's Mammary Glands, when 

FUNCTIONALLY ACTIVE. 



mg. Mammary glands. 



Teats. 



240 THE CAT. [chap. viii. 

eight nipples — four on each side, one close to the anterior, and one 
near the hinder end of the glandular structure. 

These glands become greatly enlarged when in use, especially the 
abdominal portion (Fig. 114). In the male the mammary gland is 
quite rudimentary, though essentially similar in structure to that of 
the female. 

These milk glands may be regarded as greatly enlarged and aggre- 
gated sebaceous glands, and the milk which they secrete, as a modified 
sebaceous secretion. The milk they form is an opaque white fluid, 
containing much water, with certain salts of potassium and sodium, 
with phosphoric acid, iron, milk-sugar, some albuminous matters 
(casein and a little albumen), with fats and some other substances. 

The milk being the destined food of the kitten, contains all the 
materials needed for the nourishment and growth of the young 
animal. It contains in fact a suitable and nicely balanced supply 
of nitrogenous and non-nitrogenous, albuminoid, fatty, amylaceous 
and saccharine matters. 

§ 19. In the structures last described we have found organs 
destined for the nourishment of another individual ; but we have 
next to consider organs destined for the actual fonnation of other 
individuals. Such are the organs of reproduction, or generative 
organs : the business of which is to manufacture, and to render 
serviceable certain diverse products which concur in giving rise to 
a new living organism, destined with growth to become an animal 
like that by which one or other of such products have been secreted. 

The products thus formed are essentially of two kinds, and the 
faculty of forming one or the other of them constitutes the difference of 
sex. It is only by the union of these two kinds of products that a new 
cat can be formed, and the process by which that formation takes place 
after such a union has been effected, is the process of development, the 
consideration of which will occupy us in the next chapter but one. 

But although the process of development will there be considered, 
the nature of generation may be more fitly spoken of here. The 
process of growth has been already many times referred to, and 
even in the second chapter facts as to the growth of epithelial cells, 
of cartilage and bone, were brought before the reader's notice ; and 
in the chapter on the organs of circulation, we saw how lymph 
corpuscles grow by spontaneous self-division within the substance of 
the lymphatic glands. In all these processes of growth, we have, 
indeed, already become acquainted with a sort of reproduction, for 
it is by the reproduction of the component cells of the various tissues 
that their growth is effected. The fact then of an organ secreting 
cells which detach themselves in order to perform special functions, 
is a fact which has now no novelty for us. Indeed we have met 
with a truly complex form of reproduction, in the development 
from the milk-tooth's sac of a bud or off-shoot, capable of growing 
into the permanent dental structure by which such milk-tooth is 
ultimately replaced. Nevertheless, although generation may be 
said to be a kind of growth ; yet it is a very special and peculiar 
kind of growth. By it in the first place is formed a cell capable by 



chap, viil] ORGANS OF RESPIRATION AND SECRETION. 241 

self- division and metamorphosis of growing np not into a single 
organ only, but into a perfect animal like that which produced it. 
In the second place, this reproductive cell is formed with reference to 
another kind of cell, without the concurrence of which other kind it 
is quite unable to perform its own proper function ; while that other 
kind of cell is formed exclusively — and with an admirable adaptation 
of means to ends — for the purpose of aiding the proper function of the 
first kind of cell. This reciprocal purposive relation, with the results 
of the due carrying out of the thus related processes, are amongst 
the most wonderful phenomena of the whole domain of Biology. 

One of the two reproductive elements here referred to is, as it were, 
passive, and awaits the advent of the more active element. The former 
is the female product ; the latter is the product of the male. 

In order, then, to effect reproduction, distinct sexual organs are 
required for the formation (secretion) of these two elements. But it is 
also evident that other organs are needed whereby the juxtaposition 
of these elements may be effected, and thus it is clear that the genera- 
tive organs must be of two kinds: (1) internal organs, which concern 
the formation of these elements themselves, and (2) external organs, 
which concern their transmission and conjunction. These organs 
may be expected to be different in the two sexes, as is in fact the 
case, and thus we have to consider the external and internal gene- 
rative organs, both of the male and of the female sex. 

§ 20. The male generative organs of the cat consist, in the 
first place, of two glandular structures, the testes (which are the 
essential male organs, since it is they which secrete the male gene- 
rative element). 

Two tubes, one from each testis, called the vasa deferentia, open 
into that median canal, the urethra s which, as we have already seen, 
proceeds from the anterior orifice of the bladder. This canal also 
receives the products of certain accessory glandular structures, and 
proceeds to traverse that median external body, the penis, which 
latter serves as the channel of exit to the urinary secretion as well 
as to the generative products. As it leaves the bladder, the urethra 
is surrounded by one of the accessory structures before referred to, 
namely, the prostate gland. The other accessory glands, called 
Couper's glands, are two small rounded bodies, placed one on each 
side of the urethra and in front of the prostate gland. Each vas 
deferens enters the urethra beside its fellow of the opposite side. 

The penis is a conical body, mainly composed of fibrous tissue, 
but extremely vascular. Its tissue is of two kinds, arranged 
in three masses. One mass, median, ventral, and terminal in posi- 
tion, is called the corpus spongiosum, and immediately invests the 
urethra. The other kind forms two laterally and dorsally situated 
masses, called the corpora^ cavernosa, which are placed side by side, 
and form the bulk of the organ, which is attached by its root to the 
pubes and the part of the ischia nearest the symphysis pubis. The 
distal end of the organ is called the glans, and is an expansion of the 
corpus spongiosum. It is conical and pointed, and has at its ex- 



242 



THE CAT. 



[CHAP. VIII. 



tremity the external orifice of the urethra. The organ is held 
suspended from the wall of the abdomen by a fold of integument 
which is inserted around the glans, forming what is called the 
prepuce (Fig. 115). When not sexually active, 
the penis is bent backwards towards its ex- 
tremity, a condition which makes the cat 
" retromingent." A small bone traverses the 
midst of the distal part of the penis, reaching 
almost to its extremity. The surface of the 
glans is beset with hard papillae, the points of 
which are directed towards its base. 

The corpora cavernosa and the corpus 
spongiosum are each formed of a spongy mass 
of fibrous bands, called trabecule, containing 
elastic and muscular fibres as well as nerves 
and arteries. In the intervals of these bands 
are highly distensible veins, into which a 
certain number of arteries directly open. It 
is the capacity for temporary distension by 
means of such veins which causes these tissues 
to be spoken of as "erectile" 

The urethra consists of a tube of mucous 
membrane invested by organic muscular fibres. 
It originates at the bladder, upon quitting which 
it enters a gland to be shortly described as the 
prostate. In the floor of this prostatic portion 
of the tube is a small, ridge-like prominence, 
called the verum montanum, in the midst of 
which is a narrow, slit-like depression, named 
the utricle {sitius pocularis, or vesica prostatica), 
at or within the margins of the opening of 
which the seminal ducts, or vasa differentia, 
open into the urethra. 

The term " membranous urethra" is applied 
to that portion of the tube which emerges from 
the prostate gland. Its membranous part is 
soon succeeded by its " spongy portion," i.e., 
by the part which traverses the penis. Distally, 
the urethra is lined by squamous epithelium, 
but elsewhere by epithelium of the columnar 
kind. 

The urethra of the male thus transmits both 
the renal excretion (which traverses its whole 
length) and also the sexual secretion, which 
traverses that part of it which is beyond the 
entrance of the vasa differentia. 

The prostate gland (Fig. 115, p.) is a voluminous, prominent, 

andular structure surrounding the urethra at its exit from the 

bladder, and opening into that canal by numerous apertures at the 




Fig. 115.— Male Organ 
of Generation— inferior 

SURFACE. 

u. Ureter. 
vd. Vas deferens. 
p. Prostate. 
eg. Cowpsr's gland, 
e. Erector penis muscle. 
- g. Glans penis. 
b. Bladder. 

1. One of the crura of 

the penis, with the 
ischio - cavernosus 
muscle upon it. 

2. Accelerator urinse mus- 

cle which invests the 
proximal, ventral 
part of the penis. 
A portion of the external 
skin has been left at- 
tached round the base 
of the glans. 



chap, viii.] ORGANS OF RESPIRATION AND SECRETION. 243 

side of the verum montanum. It is made up of a number of small 
follicles, which open into its excretory canals, the apertures of which 
have just been mentioned. It is invested by a fibrous coat con- 
taining many organic muscular fibres. It secretes a fluid of a 
milky appearance. 

Coupcrs glands (Fig. 115, c g) are two large racemose structures 
of firm consistency, w T ith a thick muscular envelope, placed one on 
each side of the urethra and a little beyond the prostate. Each 
opens by a single duct into the urethra at the root of the penis. 
These glands secrete a viscid fluid of unknown function. 

The scrotum is that pouch of integument which is destined to 
contain the testes, which hang within it beneath the anus and 
behind the pelvis. Although this pouch (the scrotum) is single 
externally, an inner coat — the dartos — (consisting of vascular mem- 
brane with organic muscular fibres) forms two pouches, one for each 
testis. This coat is continuous with the fascia of the abdomen and 
thigh. Within it is a layer of membrane — the spermatic fascia — 
and other envelopes of connective tissue or muscular fibres — on? 
delicate layer of the latter tissue forming w\hat is known as the 
cremaster muscle. 

Each testis is also enveloped in a pouch of peritoneum, called the 
tunica vaginalis, within which is the tunica albuginea — a dense, 
white, fibrous membrane, which immediately invests the testis itself. 

§ 21. The testes are the true male sexual glands, to which all the 
other male sexual organs are but auxiliary. Each testis is an oval 
body, which is suspended in the scrotal chamber by a cord — the 
spermatic cord — which passes forwards and inwards through the 
abdominal ring to the urethra. A conical, more or less separable 
body, known as the epididymis, lies dorsally and posteriorly upon 
the testis. As it is external to the testis itself, it is not invested by 
the tunica albuginea. One rounded end of the epididymis — called 
the globus major — is connected with the testis by certain ducts. The 
other more pointed end — the globus minor — is only united to it by 
connective tissue. 

At that portion of the testis which is adjacent to the epididymis, 
the tunica albuginea is prolonged far down into the soft substance of 
the gland, forming a septum called the mediastinum testis, or corpus 
Highmorianum, which is situated in the middle of the testis. Many 
slender cords and lamella? of connective tissue radiate from the 
mediastinum to the inner surface of the tunica albuginea, thus 
dividing that portion of the gland by imperfect partitions into conical 
interspaces, and helping to maintain the shape of the testis. The 
gland is richly supplied with blood-vessels, which ramify in the 
tunica albuginea and accompany its partitioning processes. Between 
these membranous imperfect partitions, lies the soft proper glandular 
substance of the testis, which consists of minute convoluted tubes, 
called tubuli seminiferi, because they are the immediate agents in 
seminal secretion. They are arranged in pyramidal aggregations or 
"lobules," respectively invested by the membranous imperfect par- 



244 



THE CAT 



[CHAP. VIII. 




titions before mentioned. They converge and anastomose (tubes of 
adjoining lobules anastomosing also) as they approach the medias- 
tinum and epididymis till they are greatly reduced in number, when 
they assume a comparatively straight course, and are called the 
tubuli recti, or rasa recta. These traverse the mediastinum and 
then form a network of tubes called the rete 
rasculosum, from which network other tubes, 
called rasa efferentia, arise, and these enter the 
globus major of the epididymis. 

The tubuli seminiferi are formed of connective 
tissue lined with a basement membrane and 
epithelium which is never ciliated but con- 
sists of nucleated granular corpuscles and nu- 
cleated cells, which transform themselves into 
the male generative elements. 

The structure of the epididymis is much 
more simple than that of the testis. It con- 
sists of an enormously long convoluted tube, 
into the proximal part of which the vasa 
efferentia open. 

These vasa efferentia, however, which are 
nearly straight at first, do not remain so, but 
each becomes much convoluted as it approaches 
the canal of the epididymis, so that they form 
a series of small conical masses called coni 
vasculosi, the apices of which are turned 
towards the testis and towards the apices of 
the conical lobuli of that gland. They all 
successively open into the canal of the epidi- 
dymis. This canal has its convolutions sup- 
ported by connective tissue (thus forming lobes). 
It increases in size towards the end of the globus 
minor, where it acquires thicker coats and 
becomes the vas deferens. The vasa efferentia 
are lined with ciliated epithelium, as is also 
the case with the canal of the epididymis. 
Sometimes a small tube, called a vas aberrans, 
is given off from the commencement of the vas deferens. A very 
small pedunculated structure in the vicinity of the head of the 
epididymis is called the hydatid of Morgagni. A few convoluted 
tubules (also near the head of the epididymis) are sometimes spoken 
of as the Organ of Gir aides or parepididymis. These parts are quite 
functionless remnants of a foetal structure which will be noticed 
in the chapter on Development. 

The vas deferens — the continuation of the canal of the epididymis 
— is at first much convoluted, but becoming straight extends up the 
inner side of the epididymis, and thence upwards beside the spermatic 
artery which goes to the testis, and the spermatic veins which leave 
it, — these vessels, with the vas deferens and the tissues which unite 



Fig. 116. — Diagram 

SHOWING THE ARRANGE- 
MENT of the Tubes in a 
Mammalian Testis. 

act. Tubuli seminiferi, 
coiled up in the se- 
parate lobules. 

b. Vasa recta. 

c. Rete vasculosum. 

d. Vasaefferentia,ending 

in the coni vascu- 
losi. 
I, e, g. Convoluted canal 

of the epididymis. 
h. Vas deferens. 
/. Section of the back 

part of the tunica 

albuginea. 
i, i. Fibrous processes 

running between the 

lobes. 
/ to s. Mediastinum. In 
the cat the mediastinum 
is not on one side, as 
in the above figure, but 
is nearly in the middle 
of the testis. 




MAGNIFIED 320 DIA- 
METERS, ASD THEN 
ENLARGED THREE 
TIMES. 



chap, viii.] .ORGANS OF RESPIRATION AND SECRETION. 245 

them all together, forming the spermatic cord before referred to. The 
vas deferens is made of connective tissue enclosing a muscular coat, 
the inside of which is mucous membrane, lined internally with 
columnar but not ciliated epithelium. The two vasa deferentia 
open into the urethra, as before described. 

§ 22. The special secretion of the testis consists of certain sper- 
matic filaments or spermatozoa, w hi ch by their activity remind us of 
detached cells of ciliated epithelium. They are not however the 
equivalents of such cells, but of subdivisions of such cells. Each 
spermatozoon consists of an oval flattened part called the " head " 
or " body," and of a long and very slender filamentary " tail." 

Each spermatozoon is a peculiarly shaped cell of protoplasm, con- 
taining a nucleus. The oval portion or head con- 
sists of the nucleus enveloped in an extremely 
delicate layer of protoplasm, which protoplasm 
is continued on to form the filamentary tail. 

The spermatozoa are not the immediate product 
of the testicular tubuli; these first produce ■' sperm- 
cells " or " spermospores," which constitute th<? 
epithelium lining the tubuli. From these cells Fig n7 _ Speema . 
the spermatozoa appear to be formed by sub- TOZOA OF ™" Cat - 
division ot the nucleus or each spermospore ; the 
divisions of the nucleus forming the main part 
of the head of each spermatozoon, which is 
completed from the non-nuclear substance of the dividing spermo- 
spore. 

The vibratile, lashing action of the spermatozoon, only takes 
place when it is fully developed. It will retain its power of move- 
ment for some hours after its removal from the body if immersed in 
a suitable fluid. By its lashings it effects a locomotive movement, 
and it is thus admirably enabled to advance towards its proper 
destination. Without the aid of these spermatic filaments no 
reproduction of the cat species can take place. 

§ 23. The female generative organs may, like those of the 
male, be divided into (1) the external, and (2) the interned organs — 
the latter being the essential sexual parts. The functions of the 
female organs are, however, more complex than those of the male. 
The latter are destined to simply form and discharge their products, 
but the female organs have not only to do this but also to receive 
the male product and to protect and further that developmental 
action which is initiated by the junction of that male product with 
their own. The female organs consist, in the first place, of two 
glandular structures, the ovaries, which secrete the female generative 
product, the ova. Two tubes, one for each ovary, called the 
Fallopian tubes, open into a median tubular structure, the uterus, 
which is continued onwards to the exterior by the help of another 
tube — the vagina, immediately external to which is the tiro-genital 
chamber or vestibule, which is the most external portion of the 
whole apparatus, and which opens on the surface of the body a 



246 THE CAT. [chap. viii. 

little in front of the anal aperture. At the anterior part of the 
vestibule is the opening of the urethra, which is continued to this 
point from the bladder. Just in front of the external opening of 
the urethra is a small body called the clitoris, whence two folds — 
the labia — proceed backwards (surrounding the external vaginal 
aperture), beneath which (one on each side) are two glands, called 
those of Bertholin, the ducts of which open into the vestibule. 

The urethra of the female is thus but a very short tube. It 
transmits the renal excretion only, the sexual excretion not passing 
through it. The vestibule represents the prostatic part of the male 
urethra, but there is no part answering to the spongy portion of the 
latter. There is no such part, because the clitoris (which is the 
rudimentary representation in the female, of the penis of the male, 
and is similarly formed of two corpora cavernosa, a corpus 
spongiosum and a very small ossicle) is imperforate and not 
traversed by the urethra. 

There is no representative, in the female, of the prostate gland 
of the male, but the " Cowper's glands" are represented by the 
"glands of Bertholin," which have a muscular envelope like their 
analogues in the other sex. 

There is no scrotum, because the ovaries (which are the analogues 
of the testes) are enclosed within the abdominal cavity. Neverthe- 
less the scrotum is represented by the labia which bound the external 
aperture on each side. 

We now come to parts in the female which are hardly represented 
in the male. We saw in the latter that there was a slight depres- 
sion (the " utricle " or " sinus pocularis,") in the floor of the 
prostatic portion of the urethra and between the entrance into it of 
the vasa differentia. In the female, this small depression is repre- 
sented by a deep cylindrical cavity consisting of two successive 
parts, the vagina and the uterus, but no tubes open beside it corre- 
sponding to the vasa differentia of the male cat. The vagina (which 
opens posteriorly into the vestibule, while anteriorly it opens into 
the uterus,) is formed of fibrous tissue and organic muscular fibre 
lined with mucous membrane, with numerous papillae and follicles, 
and coated with squamous epithelium. Towards the vestibule its 
muscular fibres arrange themselves as a sphincter. A few ridges 
(rugce) extend along the length of its inner surface and terminate 
abruptly at a transverse circular prominence (which may be a 
distinct fold or may be almost indistinguishable) called the hymen, 
which marks off the commencement of the vagina from the more 
externally situated vestibule. 

The uterus (Fig. 105, id and c) is a short muscular bag with 
two very long, posteriorly diverging, branches or lateral continua- 
tions — the cornua — which extend, horizontally forwards in the 
abdominal cavity. 

Its commencement, the os tincce, projects prominently into the 
hinder part of the vagina, and is beset with numerous short 



chap, viil] ORGANS OF RESPIRATION AND SECRETION. 247 

papillae. Anteriorly the cornua terminate by receiving the openings 
of the Fallopian tubes. 

The organ is formed of a mass of organic muscular fibre and 
fibrous tissue (richly supplied with vessels and nerves) and is lined 
with mucous membrane beset with simple tubular glands, which upon 
its interior surface is coated with columnar and ciliated epithelium. 

The uterus is the organ destined to shelter and nourish the ova 
from shortly after their impregnation till the litter is brought forth. 
This period is that of " pregnancy," and during it the organ in- 
creases enormously in size and capacity and in the quantity of 
muscular tissue it contains. 

The size of the uterus therefore varies extremely, according to 
whether it does or does not contain ova in process of develop- 
ment, and according to the development which such ova may have 
attained. The time of carrying the kitte~is within it, i.e., the 
period of gestation, having come to an end, the uterus begins to 
undergo powerful contractions till its contents are expelled in the 
act of giving birth, or parturition. This act accomplished, the 
organ begins again to diminish, many of its muscular fibres undergo 
a transformation into fatty matter and are then absorbed, and it 
soon returns nearly to the size which it had before impregnation. 

The uterus is held in place, partly by its continuity with the 
Fallopian tubes and vagina, partly by ligaments called respectively 
"broad," " ovarian" and " round." The broad ligaments are great 
lateral folds of peritoneum which embrace the uterus with its 
cornua and the Fallopian tubes and ovary. The ovarian ligaments 
are short fibrous cords which extend one from the end of each uterine 
cornu to the adjacent ovary. The round ligaments are two delicate 
fibrous cords which pass one from each of the sides of the uterus 
to the brim of the pelvis. 

The Fallopian tubes (Fig. 105, f t ) have been already mentioned 
as extending along within the folds of the broad ligament to the 
extremity of the cornua of the uterus — one Fallopian tube opening 
into each cornu after following a much convoluted course. 

At its opposite extremity each Fallopian tube ends in an ex- 
panded, trumpet-like termination surrounded by certain irregular 
processes or fimbria*, one of which, longer than the others, is 
attached to the adjacent ovary. The fimbriated and expanded 
end of the Fallopian tube has been named the morsus diaboli. 
The cavity within the Fallopian tube is extremely minute, and 
opens externally in the midst of its fimbriated extremity. 

Each Fallopian tube is, as has been said, coated externally 
with peritoneum; within this is a layer of longitudinal organic 
fibres, and within this again 'a circular layer. Within all else is 
the mucous lining (which forms longitudinal internal folds,) 
coated with columnar and ciliated epithelium. At the orifice of 
the Fallopian tube the mucous membrane which lines its interior 
becomes actually continuous w 7 ith the peritoneal coat which invests 
it externally. Thus, in the female (unlike the male) the perito- 



248 



THE CAT. 



[chap. VIII. 



neum is not a shut sac but has two distinct perforations, the 
mouths of the Fallopian tubes, which indirectly place its cavity 
in connection with the external surface of the body. 

§ 24. The ovary is the essential secreting organ of the female 
sex, corresponding to the testis of the male. There are two such 
bodies, one on each side, as there are two testes, but, unlike the 
latter, the ovaries are each a completely closed sac or follicle, and, 
though each has its excretory duct — the Fallopian tube — this duct 
has no permanent connexion with its gland (as the vas deferens has 




Fig. IIS.— Section of the Prepared Ovary of the Cat— magnified six diameters. 



1. Outer covering and free border of the ovary. 
1'. Attached border. 

2. The ovarian stroma, presenting a fibrous and 

vascular structure. 

3. External fibro-nuclear substance. 

4. Blood-vessels. 

5. Ovigerms in their earliest stages, lying near 

the surface. 

6. Ovigerms which have begun to enlarge, and 

to pass more deeply into the ovary. 

7. Ovigerms, round which the Graafian follicle 

and tunica granulosa are now formed, and 



which have passed somewhat deeper into 
the ovary, and are surrounded by firm 
fibrous stromal 

8. More a ivanced Graafian follicle, with the 

ovum imbedded in the cells of the pro- 
ligerous disc. 

9. The most advanced follicle, containing the 

ovum, and approaching the surface. 
9'. A follicle from wh.ch the ovum has acci- 
dentally escaped. 

10. Corpus luteum, presenting radiated columns 

of cellular structure. 



with its testis), but only a temporary one. The ovary is of an 
oval shape (like the testis). It lies deeply in the dorsal and lateral 
part of the abdominal cavity, hidden by the intestines, and en- 
veloped in a fold of peritoneum which forms its outer coat. The 
inner end of the gland is attached to the uterus by a dense cord, 
already mentioned as the ligament of the ovary. At the anterior 
border of the gland is a depression called the hilus, where the blood- 
vessels enter, and which is the only part not invested by the 
peritoneum. Beneath the outer or serous coat of the ovary is its 
second or proper covering, the tunica albuginea, often compared with 
the same part of the testis. It serves to maintain the organ in 
shape, but really is but a condensed part of what is . beneath it, 
namely, the proper tissue — the stroma, or parenchyma, of the ovary. 
This substance is of a pink, or red, colour (from the number of 
vessels it contains), and is made up of connective tissue, with nerves, 



chap, viii.] ORGANS OF RESPIRATION AND SECRETION. 249 



blood-vessels, and some muscular fibres. It has an outer epithelial 
and contains embedded vesicles of various sizes — called 



covering, 



the ova* or true female sexual 



Graafian follicles — containing 
product. 

In the stroma of the ovary there is but little fibrous connective 
tissue. It is made up mainly of large spindle-shaped cells,* which 
surround the Graafian follicles, being arranged concentrically about 
them. 

Upon dividing the ovary, vesicles of various sizes are seen within, 




ssf^ai 



Fig. 119. — Portion of the Section of the prepared Cat's Ovary, represented in the 

PRECEDING FIGURE, MORE HIGHLY MAGNIFIED. 

1. Outer covering of the ovary. 

2. Fibrous stroma. 

3. Superficial layer of fibro-nuclear substance. 



Deeper parts of the same. 

4. Blood-vessels 

5. Ovigerms forming a layer near the surface. 

6. One or two of the ovigerms sinking deeper, 

and beginning to enlarge. 

7. One of the ovigerms further developed, now 

enclosed by a prolongation of the fibrous 
stroma, and consisting of a small Graafian 



follicle, within which is situated the ovum 
covere I by the cells of the discus proligerus. 

A follicle further advanced. 

Another which is irregularly compressed. 

The great r part of the largest follicle— in 
which the following parts are seen : a, 
cells of the membrana granulosa lining the 
follicl ! ; b, the reflected portion, named 
discus proligerus ; c, vitellus or yelk part of 
the ovum, sui rounded by the zona pellucida , 
d, germinal vesicle ; e, germinal spot. 



and these are much more numerous in the very young animal than 
in the adult. 

These vesicles, or " Graafian follicles," are naturally spherical or 
oval, and have three coats. The first and most external of these, 
the tunic of the ovisac, or tunica fibrosa, is a fibrous, vascular 
membrane, containing oval nuclei, but destitute of oil globules. 
The second coat is the ovisac, formed of connective tissue, rounded 
cells, and minute oil globules. The third coat (if it should be 
really recognized as distinct) is the membrana granulosa, consisting 



* See Klein and Noble Smith's Atlas of Histology. 



250 THE CAT. [chap, viii 

of a stratum of nucleated cells lying in close contact with the inner 
surface of the ovisac. Enclosed within these layers is a clear and 
colourless albuminous fluid, and a small, rounded body, embedded 
in a cellular mass, the discus proligerus or cumulus, on the inner 
surface of the membrana granulosa. This rounded body is the 
ovum — the special female sexual element, The larger Graafian 
vesicles are found at, or near, the surface of the ovary, and it has 
been found that they approach the surface as they develop. They 
are indeed primitively formed at the periphery, but they subse-' 
quently sink inwards, and afterwards return once more to the 
surface. At first the Graafian vesicle is but the envelope of the 
minute ovum it contains. It subsequently increases, so as to exceed 
in size the contained ovum to a greater and greater, and ultimately 
to a very great, degree. 

§ 25. The ovum is a minute spheroidal mass of protein substance, 
about the T ] ? to y^o- of an inch in diameter. It consists of an 
external tough, elastic, and relatively thick tunic, the zona pellucida, 

which is quite transparent and struc- 
tureless, though apparently perforated by 
many excessively minute pores. Exter- 
nally the zona pellucida is invested by a 
layer of epithelial cells, the tunica granulosa, 
which is embedded in the cellular mass, 
the cumulus, which connects the ovum 
Fig. 120.— the Ovum, greatly with, the innermost coat (or membrana 
magnified. granulosa) of the G raafian vesicle. Within 

Its cS^Sli^tlTadTaS the zona pellucida is the yelk mass (as 
lmear structure within this SO me say enclosed within a distinct, but 

is the yelk substance, with , r 7 , ,. . , „ . ', 

granules and small oil gio- extremely delicate, membrane) of protoplasm 

bules ; towards one side is the j i u •,!_ m l l. i 

la.ge germinal vesicle con- and granular matter, with oil globules, 

taming the germinal spot. b ut having within it a nucleus termed the 

germinal vesicle, about the T 4-o of an inch 

in diameter, and enclosing a minute opaque body or nucleolus, known 

as the germinal spot, which is from the ^Vo to the ¥3 Vo of an 

inch in diameter. 

Beside the ovary, within the folds of broad ligament, are certain 
small tubules, which together constitute what is called the par- 
ovarium. This small body is analogous to the organ of Giraldes, 
found in some male animals. Connected with the parovarium is 
a delicate, cylindrical structure called Gaertner's duct, which runs 
from the parovarium down the side of the body of the uterus, when 
it ends blindly.* 

A small pedunculated body in the vicinity of the parovarium, or 
of the mouth of the Fallopian tube, is called a hydatid in the 
female, as are corresponding structures in the male. 

The function of the ovary is of course mainly to secrete ova, but 
the formation of the Graafian vesicles, in which the ova are 

* Mr. Alban Doran has ascertained these points by careful dissections. 




chap, viii.] ORGANS OF RESPIRATION AND SECRETION. 251 

contained, must also be reckoned as a part of its function. The 
development of ripe ova — or ovulation — begins to take place in the 
first year of the animal's life, and is thenceforth continued till the 
bodily decay of age sets in. 

It takes place at frequent intervals,* and culminates in the 
rupture of one or more Graafian vesicles, with the discharge of the 
ovum or ova from the surface of the ovary through its peritoneal 
coat into the peritoneal cavity. This process is generally accompanied 
with more or less* constitutional disturbance, and an increased 
supply of blood to the generative organs. By a wonderful and 
quite unexplained process of reflex action, the rupture of a Graafian 
vesicle is accompanied by a spontaneous application of the fimbriated 
end of the Fallopian tube to the place of rupture. In this way the 
discharged ovum, instead of being cast loose into the peritoneal 
cavity, is received into the mouth and canal of the Fallopian tube, 
and so conveyed onwards, by its ciliated lining, to the cavity of the 
icterus. The walls of the ruptured Graafian vesicle then increase in 
substance, and thus give rise, for a time, to a yellowish mass termed 
the corpus luteum (Fig. 118, 10 ). 

Simultaneously with the constitutional disturbance just referred 
to, the sexual appetite is inflamed, and the animal becomes " at 
heat." 

The formation of the ova, unlike that of the spermatozoa, does not 
take place in distinct tubes,f but in the seemingly non-tubular 
substance or stroma of the ovary. The process of the formation of 
the ova is so different from that of spermatozoa, and is so closely 
connected with embryonic conditions, that its description is more in 
place under the head of development. Nevertheless it may be here 
observed that each ovum is a modified and enlarged cell of the 
epithelial tissue of the ovary, which is thus, as before pointed out, 
not the equivalent of a spermatozoon, but of a " sperm- cell " or 
" spermospore," which is the parent of various spermatozoa. The 
incipient ovum — or ovigerm — becomes surrounded by other smaller 
cells, which subsequently, by multiplication and separation form 
both the "tunica granulosa " of the ovum and the "inembrana 
granulosa " lining the Graafian follicles — fluid gradually forming 
and greatly increasing between these at first closely juxtaposed 
layers. The outer envelope of the Graafian follicle appears to be 
formed by other epithelial cells, and by a special growth of the 
ovarian stroma around the developing ovum. 

* It is difficult to ascertain how often, I settled; but the wide divergence of form 

as the adult unimpregnated female cat | which exists between the mature sexual 

often seems to be almost continually . glands of the two sexes is manifest and 

ready for reproductive activity. | indisputable. For some recent observa- 

+ Whether the composition of the i tions made with reference to this obscure 

ovary and the formation of ova are question, see a paper by Mr. E. A. 

essentially "tubular,"' is a question Schafer, F.R.S., in Pro. Roy. Society, 

which cannot yet be regarded as tin ally j 18S0, p. 245. 



CHAPTER IX. 

THE CAT'S NERVOUS SYSTEM AND ORGANS OF SENSE. 

§ 1. We have now to consider that system of parts which ministers 
not merely to the processes of organic life, but also to motion, sensa- 
tion, and cognition. It may therefore be considered as the highest 
system of parts of which the cat's body is made up. It is so closely 
connected with motion, and motion is so closely connected with 
sensation, that these functions would have been here treated of to- 
gether but for three reasons : The first reason was that the consider- 
tion of the muscles, as forming so large a part of the body, could not 
conveniently be postponed ; secondly, the intimate relation of the 
muscles to the bony levers they move, made it desirable to consider 
them immediately after the description of the skeleton ; and thirdly, 
the study of the nervous system can hardly be profitably pursued till 
acquaintance has been made with all the main organs and parts to 
which the various nerves are distributed. Such an acquaintance 
has now been made, and the nervous system remains alone for our 
ultimate consideration, both as to its structure and as to its functions 
— the most conspicuous of the latter being sensation. All forms of 
merely physical activity, such as light, heat, chemical change, &c, 
are indeed separated by a gulf from the activities of organic growth 
and reproduction, but a gulf hardly less marked divides these latter 
faculties from one so altogether peculiar and sui generis as is the 
wonderful power of feeling and cognition. 

But although the nervous system is that which ministers to 
sensation — that without which we have no evidence that sensation 
is even possible — nevertheless such a definition of its functions would 
be very incomplete, The nervous system is the immediate cause of 
motion, and performs, as we shall see, an intermediate part between 
the organism containing it, as a whole, and the environing world, 
since it receives influences from the latter which may excite cor- 
relative activities in the organism without, as well as with, the 
accompaniment of sensation. 

It has been before said that an organism is a body in which each 
part is reciprocally end and means. In animal organisms, this re- 
ciprocity is generally ministered to and effected by the agency of the 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 253 

nervous system, and this reciprocal activity is mainly effected with- 
out " feeling" coming into play. 

Thus the nervous system may be defined as the great co- 
ordinating system of the body ; co-ordinating the action of the 
parts of the body one with another, co-ordinating the action of such 
parts with relation to surrounding influences and conditions, and 
also co-ordinating the action of the body as a whole with relation 
to such influences and conditions — the activity of the nervous system 
being more or less frequently accompanied by acts of sensation. 

§ 2. Sensation is incapable of definition, since to be understood 
it must be experienced, and every man must know what it is to have 
a feeling who knows anything whatever, as " sensations " are with 
us the indispensable antecedents of ideas, and therefore of all know- 
ledge. Sensation, however, may be described as a special and alto- 
gether peculiar vital organic activity, which accompanies certain 
actions of the nervous system occurring under the requisite con- 
ditions. 

§ 3. That system of parts, the nervous system, the nature of 
which has just been defined, is made up, like the skeleton, of two 
great divisions, one axial, the other peripheral. Besides these, that 
part of the peripheral system which especially supplies the viscera, is 
commonly reckoned as distinct, under the name of the sympathetic 
system. The whole consists of a peculiar tissue (to be shortly 
described), forming a white or grey pulpy mass in the form of bulky 
aggregations, and of cords or threads, which radiate in all directions 
from such aggregations. 

The axial part of the nervous system is that bulky aggregation 
of nervous or neural matter, which occupies the cranial cavity and 
the neural canal of the vertebral column (Fig. 2, n), that is to say, 
it is the brain and spinal cord which are together spoken of as the 
cerebrospinal axis. 

The peripheral part of the nervous system is that system of cords 
or threads of neural matter which are called nerves, and which 
proceed out from the cerebro- spinal axis to all parts of the body. 
Scattered amongst them every here and there are certain aggrega- 
tions of nervous matter — in rounded or irregularly-shaped masses 
of various sizes — called ganglia. That portion of the peripheral 
part of the nervous system called the sympathetic (and which, as 
just observed, is specially distributed to the viscera) differs somewhat 
from the rest as to its minute structure. 

§ 4. Nervous tissue is a soft, nitrogenous substance of very com- 
plex chemical composition. It is reducible into water, albuminoid 
matter, fatty and extractive matters, and sundry salts. Different parts 
of it contain from 73 to 85 per cent, of water, 7 to 10 per cent, of 
albuminoid matter, and from 5 to 15 per cent, of fat. 

The fatty matters consist of cerebric, glycero-phosphoric, and 
palmitic acids, with olein, margarin, palmitin, and cholesterin. 
From brain-ash the following percentage of different substances 
has been obtained. Phosphate of potash, 55 "24 ; phosphate of soda, 



254 



THE CAT. 



[CHAP. IX. 



22*93 ; phosphate of iron, 1'23 ; phosphate of lime, 1-62 ; phosphate 
of magnesia, 34 ; chloride of sodium, 4'74 ; sulphate of potash, 
1*64 ; free phosphoric acid, 9'15 ; and silicic acid, 0'41. 

The structural elements of nervous tissue are mainly of two 
kinds : (1) fibres, and (2) nerve-cells or corpuscles. The former oi 
these elements makes up the bulk of the peripheral part of the 
nervous system, while the corpuscles abound in its axial portion and 
in its scattered ganglia. 

The nerve fibres are again divisible into two kinds : (1) the 
white or tubular nerve fibres, and (2) the grey on: pale fibres. 

The white fibres, which form the bulk of all the nerves except 
those of the sympathetic system, are nearly cylindrical filaments 





Fig. 121.— White Nerve Fibres. 



A. White or medullated nerve-fibres, showing 

their sinuous outline and double contours. 

B. Diagram showing the parts of a medullated 

fibre, viz. : 

1 — 1. Primitive sheath. 

2—2. The white substance, or medullary 

sheath. 
3. The axis-fibre, or axis-cylinder — some- 
times called the primitive band. 
C Diagram intended to represent appearances 



occasionally seen in the tubular fibres, viz. 
1 — 1. Membrane of the tube, seen at part 
where the white substance has separated 
from it. 

2. A part where the white substance is 
interrupted. 

3. Axis projecting beyond the broken end 
of the tube. 

4. Parts of the contents of the tube which 
have escaped. 



which, during life, seem composed of a clear, oily, semi-fluid sub- 
stance, but after death, appear as composed of a delicate structureless 
outer membrane — the primitive sheath (like the sarcolemma of muscle 
fibre), provided with large nuclei, and containing fatty fluid termed 
the Medullary sheath or white substance of Schtvann, through which 
runs a thin central thread of albuminoid matter called the axis cylinder. 
The largest of these white nerve-fibres has a diameter of about 
the tsW °f an i ncn > Du ^ some °f on ly -nro-o-o- They may be larger 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 255 

at other parts of its course than at their origins or terminations. The 
terminations of nerves, whether they end peripherally or centrally, are 
often spoken of as " end organs.'" White nerve-fibres run side by 
side in a bundle, bound together by delicate connective tissue, which 
also forms a sheath for them called the neurilemma. In spite of 
their close proximity these fibres have never been observed to 
anastomose, nor have single fibres been seen to branch till within a 
microscopic distance of their termination. This ultimate branching 
may be due to the axis cylinder really consisting of distinct fibrils 
bound together, as a longitudinal striated appearance they sometimes 
exhibit would seem to indicate. On the other hand, by the action 
of nitrate of silver they may be made to exhibit a transverse striation 
like that of muscular fibres, so that the meaning of either of these 
appearances is problematical.* 

The grey or pale fibres are chiefly found in the nerves of the 
sympathetic system, but the olfactory nerves also are entirely com- 
posed of them. They are from -g-oVo to ^oVo- of an inch in diameter, 
and are devoid of that apparent distinctness of parts characterising 




Fig. 122. — Nerve-cells from the outer grey portion of the Cerebellum, magnified 

260 DIAMETERS. 



act. Cells, each containing a nucleus, with a 

distinct nucleolus. 
6 &. Simple unbranched processes. 



cc', del'. Branches radiating in different direc- 
tions, and ramifying in various degrees. 



the white fibres. They appear translucent, homogeneous, and slightly 
granular, and exhibit at intervals oblong nuclei, which have been 
supposed to belong to the sheaths of such nerves. 

Nerve cells, or nerve corpuscles, are very different in appearance 
from nerve fibres. Each consists of a round, oval, pyramidal, club- 
shaped, pear-shaped, or many-cornered microscopic body, formed of 
protoplasm, and which may appear clear or granular according to cir- 
cumstances (perhaps of observation), and which contains a nucleus 
with one or more nucleoli. Some of these cells are devoid of processes 



* There now appears to be reason to suppose that the axis cylinder is really 
segmented. 



256 TEE CAT. [chap. ix. 

(and this, for the most part, is their form in ganglia), many have 
but one, very many have two or more — conditions denoted by the 
terms " apolar," " unipolar," " multipolar." Sometimes a process 
from one cell may be seen to join a process from another cell. 
Sometimes a process from a cell appears to continue on as the axis 
cylinder of a nerve. Nerve fibres certainly often appear to end close 
to cells, but there is as yet much dispute as to the connexions between 
them and between the processes of different cells. A desire to serve 
a particular theory has certainly given rise to much exaggeration as 
to the amount — often even as to the existence — of such connexions. 
In most cases the processes seem simply to ramify and become finer 
and finer till they cease to be distinguishable. 

Neuroglia is a substance which immediately surrounds the fibres 
and cells, and which has been supposed to be a peculiarly modified 
form of connective tissue. It is a semi-solid matrix which appears 
granular, though it may really be structureless — its granular 
appearance being the result of a coagulation. 

Such being the nature and minute constituents of the nervous 
system, its great mass, the cerebro-spinal axis, is said to be made up 
of white and of grey nervous matter. The former consists of white 
fibres only, while the grey matter consists very largely of nervous 
corpuscles, and is more vascular. Throughout the whole length of 
the spinal part of the cerebro-spinal axis the grey matter lies towards 
the middle of the whole nervous mass, the white matter being 
external. In the cerebral part of the same axis, however, the grey 
matter extends from within and expands over its surface. Although, 
the cerebro-spinal axis is very vascular, yet the arteries and veins 
which traverse it are very minute. 

5. The cerebro-spinal axis is invested and protected by tfhree 
membranes, enclosed one within the other. 

The first of these is called the dura mater > and is composed of 
thick, dense, inelastic fibrous membrane, free and smooth on its 
inner surface, but closely connected externally, in the skull, with the 
inner surface of the cranial bones, of which it forms the periosteum. 

In the spinal column it does not constitute the periosteum of the 
neural canal, but is only connected with the inner surfaces of the 
vertebra by loose areolar tissue and fat, and by slips of fibrous 
membrane. 

In the cranium the dura mater sends inwards two folds of membrane. 

The first of these is longitudinal, and is called the falx cerebri, 
and extends from the front of the skull to the occiput, depending 
from the middle of the cranial vault. 

The second fold is the tentorium, which extends forwards and 
downwards from the posterior margins of the parietal bones. It is 
also attached to the upper edge of the petrous portion of each 
temporal bone. The tentorium, as we have seen in the third 
chapter, becomes ossified in the adult cat. 

The second of the three membranous envelopes is called the pia 
mater, and is a very delicate, vascular membrane, which is closely 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 257 




applied to the surface of the cerebro-spinal axis and conveys its 

minute arteries to it (Fig. 123, c). It is thicker and less vascular on 

the spinal cord than on the brain. 

At the roots of the nerves it 

becomes continuous with the 

neurilemma. 

The third membrane is called 
the arachnoid, and is a serous 
membrane forming a closed sac 
and containing a fluid. 

The outer, or parietal, wall 
of this sac consists of a layer 
of flattened and nucleated, poly- 
gonal, epithelial cells, intimate- 
ly connected with the dura 
mater (both cranial and spinal) 
external to it. 

The inner, or visceral, wall 
of the sac is a distinct mem- 
brane investing, but not inti- 
mately, the pia mater, the 
foldings of which it does not 
follow — a space, the sub-arach- 
noid space, existing between 
them and containing a watery 
secretion. A series of attach- 
ments, called the ligamentum 
denticulatum , connects the spinal 
part of the arachnoid to the 
spinal dura mater — one existing, 
on each side, between each pair 
of nerves issuing from the spinal nervous axis. 

§ 6. The spinal cord, or mvelon, is the more or less cylindrical 
mass of nervous matter- of varying dimensions, enclosed within the 
neural canal of the spinal column, extending backwards from the 
margin of the foramen magnum of the skull. 

It remains of considerable size thence backwards till it reaches 
the hinder part of the lumbar region and sacrum, where it contracts 
to a slender filament, the filum terminate, which extends on into 
the tail. 

The general form of the spinal cord is cylindrical, but it is a little 
flattened from above downwards. It becomes somewhat broadened 
out in two places. The first of these, called the cervical enlarge- 
ment, extends from the third cervical to the first dorsal vertebra. 
The second, termed the lumbar enlargement, is situated at the las" 
dorsal vertebra, whence the myelon tapers till it ends in the " filum 
terminale." 

The cord is traversed by a deep median fissure both below and 



Fig. 123. — Brain in situ, the upper part of 

THE SkQLL BEING REMOVED. 

On the right side aTl the membranes are re- 
moved. The pia mater (with its vessels) 
remain on the left side. 

c. Cerebrum invested oy pia mater. 

ce. Cerebellum. 

cr. Crucial sulcus. 

/: Frontal bone. 

fs. Frontal sinus. 

i. Superior lateral gyrus. 

vi. Middle lateral g rus. 

e. Inferior lateral gyrus. 

z. Zygoma. 



258 



THE CAT. 



[criAr. ix. 



dorsally, of which the first or "anterior* median fissure" is the 
more distinct, and a process of the pia mater is prolonged into it, 
which is not the case as regards the posterior median fissure. 

Each lateral half of the spinal cord is also marked by two longi- 




Fig. 124.— Different views of a portion of the Spinal Cord from the Cervical 
Region, with the Roots of the Nerves, enlarged (Allen Thomson). 



In A the ventral or anterior surface is shown, 
the anterior nerve-root of the right side 
being divided ; in B, a view of the light side 
is given ; in C, the anterior or upper surface 
is shown ; in D, the nerve-roots and ganglion 
are shown from below. 

1. The anterior median fissure. 

2. Posterior median fissure. 

3. Anterior lateral depression, over which the 

anterior nerve-roots are seen to spread. 



4. Posterior lateral groove, into which the pos- 

terior roots are seen to sink. 

5. Anterior roots passing the ganglion. 
5'. In A the anterior root divided. 

6. The posterior roots, the fibres of which pass 

into the ganglion, 6'. 

7. The united or compound nerve. 

7'. The posterior primary branch, seen in A and 
D to be derived in part from the anterior 
and in part from the posterior root. 



tudinal furrows, of which the posterior, or posterior lateral fissure, is 
far the more distinct. These furrows serve to define what are called 
the "columns" which make up the cord — each lateral half of it 
being divided into an anterior, a lateral, and a posterior column. 
Nervous fibres (the roots of the spinal nerves) pass out at the anterior 
and posterior lateral furrows. 

As the nerves which so pass out traverse the intervertebral 
foramina of the spinal column, and as the spinal cord stops (as has 
been said) much short of the hinder termination of the vertebral 
neural canal, it comes to pass that the nerves which pass out at the 
sacral foramina have run back for a longer or shorter distance within 



* The terms "anterior" and "pos- 
terior " refer to human anatomy, which 
originated these names - applicable to 



man with his upright attitude, but 
unfortunate as applied to a quadruped 
like the cat. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 259 

the neural canal till they come to the foramina appropriated to them 
respectively. Thus a bundle of nerves passes backwards in the 
hinder part of that canal, on each side of the filum terminale, and 
the whole bundle of such fibres goes by the name of the cauda 
equina. 

The spinal cord is composed principally of white fibres, while the 
grey matter within it is so aggregated as to present the appearance, 
in transverse sections, of two crescentic masses with their con- 
vexities adjacent and placed one in each lateral half of the cord 
(Fig. 124, C). 

Each grey crescent ends in what is called an anterior and 
posterior horn, which approach respectively to the anterior and 
posterior lateral furrows. The posterior horn is long, with a narrow 
end. The anterior horn is shorter and thicker, with a rounded end. 




125.— Lateral view of the Brain. 



F. Frontal lobe. 
T. Temporal lobe. 
61. Olfactory lobe. 
m. Medulla oblongata. 
cb. Cerebellum. 
v. Pons Varolii. 

S. Sylvian fissure (the Sylvian fissure is the 
sulcus wiiich passes backwards and some- 



what upwards from the spot to which the 

letter S has been made to point. 
s. Superior external gyrus. 
m. Middle ext rnal gyrus. 
i. Inferior external gyrus, 
o. Supra-orbital sulcus, 
c. Crucial sulcus. 
h. Hippocampal gyrus. To the right of h is 

seen the cut end of the left optic nerve. 



The two crescents are united together by a band of grey tissue 
running across transversely at the bottom of the posterior median 
fissure, and called the grey or posterior commissure. Another band 
of white tissue also runs transversely across at the bottom of the 
anterior fissure, and is called the white or anterior commissure. 

A minute central canal runs backwards along the whole length 
of the spinal cord and into the filum terminale. It traverses the 
posterior or grey commissure, and is lined with a layer of cylindrical 
cells of ciliated epithelium. It is called the canalis centralis. 

§ 7. The brain, or excephalox, is that enlarged part of the 
nervous centres which is contained within the cranium and is enve- 
loped by the three membranes already described. It is a mass of soft, 
but more or less solid, matter which fills up the whole cranial cavity, 
fitting into all those depressions which we have found to exist in 
the floor and other parts of that cavity. It consists of two large but 
very unequal parts, termed respectively the cerebrum and cerebellum, 

s 2 



260 



THE CAT. 



[CHAP. IX. 



and of smaller portions which connect these together and with the 
.spinal cord, of which the brain (as has been already observed) is, as 
it were, the greatly enlarged, anterior termination. 

The largest portion of the brain by far is the cerebrum ; which is 
made up of two great masses termed hemispheres, placed side by 
side, and forming the anterior, upper, and lateral parts of the brain. 
Each cerebral hemisphere is considered to principally consist of two 
main parts or lobes. The more anterior of these is called the 
frontal lobe, 'and it includes nearly the anterior half of each hemi- 
sphere. The other is the temporal lobe, which forms a lateral and 
inferior prominence, which lies in the " internal temporal fossa " of 
the inside of the skull.* The posterior, inner, and upper portion of 
each hemisphere may be regarded as a slightly and indistinctly 
developed posterior lobe. The hemispheres are united with the 
hinder part of the brain mainly as follows : — The spinal cord on 
entering the skull becomes modified and takes the name of the 
medulla oblongata, and this is the hindmost part of the base of the 
brain. Continuing forwards the medulla divides into two large 
branches, the crura, which pass respectively one into each cerebral 
hemisphere, and thus connect them with the spinal column. On 
the dorsal surface of this continuation of the spinal cord into the 
skull, is placed the cerebellum (or second largest portion of the brain), 
while on its ventral surface is a prominent mass of transversely 
disposed fibres — the pons Varolii — which, as it were, wraps round 
the anterior end of the medulla on its under surface, and covers in, 
ventrally, its divergence into the crura, which thus appear to issue 
from above the anterior margin of the pons. The brain contains 
within it certain cavities, which, with one exception, are the greatly 
enlarged and complexly shaped continuation forwards of that 
minute canal (the " canalis centralis ") which * we have seen to 
traverse the spinal cord for its whole length. The different por- 
tions of this curiously expanded cavity within the brain are termed 
ventricles, and they are lined by a delicate epithelial membrane 
termed the ependyma. This ventricular cavity extends forwards 
beneath the cerebellum and above the pons Varolii, and as it is 
mainly bounded below (in front of the pons Varolii) by the 
crura and certain other structures between them, so it is bounded 
above (between the cerebellum and the cerebrum) by a variously 
formed layer of brain substance, which will be described further on, 
and which constitutes a minor bond of union between the cerebrum 
and the parts behind it. From the anterior and lower part of each 
hemisphere there proceeds forwards a body which consists of a 
cylindrical prolongation of brain substance, ending in a rounded 
expansion. These two bodies are called the olfactory lobes. f They 
lie within the olfactory fossa of the cranium. 



* See ante, p. 83. 

t In human anatomy they are often 
called the olfactory nerves. But in fact 



the true olfactory nerves come from 
them. 



chap. ix.l NERVOUS SYSTEM AND OBGANS OF SENSE. 261 



On removing the upper part of the skull (with the ossified 
tentorium and the unossified part of the dura mater) the surface of 
the brain comes into view as an ovoid, convex mass, consisting of 
two large anterior portions, with a few large contorted prominences 
on their surface, and a smaller pos- 
terior part marked with numerous 
small transverse folds or furrows. 
The two large anterior portions 
are the cerebral hemispheres, the 
median, posterior part is the cere- 
bellum — the anterior part of the 
upper surface of which is overlapped 
by the hinder portions of the cere- 
bral hemispheres. The anterior ends 
of the two olfactory lobes are also 
to be seen projecting in front of the 
middle of the anterior end of the 
cerebrum (Fig. 126, ol). The median 
line which divides the cerebrum 
into its two lateral halves, or hemi- 
spheres, is called the great or 
median longitudinal fissure. The 
smooth, contorted prominences on 
the surface of the cerebrum, are 
called the convolutions or gyri, the 
depressions which separate them 
are termed sulci, or fissures. These 
gyri and sulci are distinguished by 
definite names ; but it will be better 
to defer their description till a further 
acquaintance has been made with, 
the brain as a whole, and with all 
its main constituent portions. The 
pia mater so closely invests the brain 

that it passes down not only into the great longitudinal fissure, but also 
into all the sulci of the cerebrum and into the numerous folds on 
the surface of the cerebellum. The dura mater passes into the 
great longitudinal fissure (the membranous fold dipping into it being, 
as before said, known as the falx), and between the cerebrum and 
cerebellum (the structure known as the tentorium), but it does not 
descend into the minor depressions of the brain surface. 

If the two cerebral hemispheres be pushed apart, a large trans- 
verse white band of fibres, called the corpus callosum, will come into 
view, which band connects the two hemispheres for rather more 
than the middle third of their autero- posterior extent (Fig. 129, cc). 

If the hinder ends of the cerebral hemispheres be forcibly divari- 
cated, then the layer of brain substance, before spoken of as extending 
forwards from the front of the cerebellum, will come into view. 
Upon its surface, immediately in front of the cerebellum, two pairs 




Fig. 126.— Upper Surface of Brain, 
showing the deep longitudinal fis- 
sure dividing the two hemispheres 
and the Cerebellum behind them. 

c. Crucial sulcus. 

s. S iperior external gyrus. 

m. Middle external gyrus. 

i. Inferior external gyrus. 

v. Vermiform process of cerebellum. 

ol. Olfactory lobe. 



232 



THE CAT. 



[CHAP. IX. 




of rounded prominences may be remarked. These are known as 
the corpora quadrigemina, and the hinder pair, called the testes, are 
rather larger than the anterior pair, which are called the nates 
(Fig. 127, ns). The corpora quadrigemina are solid, and do not 
contain any internal cavity. In front of the midst of the anterior 
pair, is a solitary prominence named the pineal gland. 

Just in front of and external to the corpora quadrigemina, there 

is on each side a small prominence, 
called the corpus geniculatum. It is 
sometimes called the internal corpus 
geniculatum, because, in man, there is 
a second, contiguous, but more ex- 
ternally placed prominence, named the 
external corpus geniculatum — a structure 
which in the cat is hardly to be dis- 
tinguished. 

The cerebellum is attached to the rest 
of the brain by three pairs of processes 
or crura. The first of these are included 
in the fold of brain substance just de- 
scribed. For this fold is exceedingly 
thin at the middle of its hinder part 
— called the valve of Vienssens — so that 
the two thicker portions which laterally 
border the thin part, are reckoned as 
a pair of crura and spoken of as the 
processus a cerebello ad testes, on 
account of the parts they connect. The 
second pair of crura of the cerebellum 
are the two lateral continuations up into it of the two sides of the 
pons Varolii, and these are much the largest crura, and form the 
principal connexions of the cerebellum with the rest of the brain. 
The third pair of crura are the inferior peduncles of the cerebellum, 
or restiforni bodies, which are the continuations upwards and for- 
wards of the posterior and part of the lateral columns of the spinal 
cord. They diverge as they advance. 

The cerebellum is darker than the cerebrum. Its greatest 
diameter is transverse, and it consists of two lateral lobes and a 
median portion, called the vermiform process. The numerous more 
or less parallel grooves on its surface indicate so many folds of grey 
substance enclosing white matter within. The central mass of the 
cerebellum is composed of white matter, and lamellar processes of 
the same substance proceed in all directions from that central mass 
into the darker enveloping layer. The cerebellum lies in that fossa 
of the cranial cavity which we have seen to be bounded in front by 
the petrous parts of the temporal bones, and behind by the line of 
attachment of the tentorium to the occipital and parietal bones. 

The medulla oblongata lies upon the basi-occipital. Its anterior 
inferior surface is marked by a median groove, on each side of 



Fig. 127. — Upper Surface of 
Brain of Cat — the Cerebral 
Hemispheres being widely di- 
varicated, TO SHOW THE PARTS THEY 
NATURALLY COVER. 

ns. Nates. 

pn. Pineal gland. 

ts. Testes. 

Sv. Superior vermis of cerebellum. 

Cc. Corpus callosuin. 

5. Fifth ventricle. 

Cs. Corpus striatum. 

Cg. Corpus geniculatum. 

Th, The optic thalamus. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 263 

which is an antero-posteriorly extending portion of white substance 
(going to the Pons), called the anterior pyramid. Outside each such 
pyramid is a small, more or less hidden, oval structure, termed the 
olivary body, and external to and behind each of these is the hand 
of nervous tissue already spoken of as the restiform body. The 
middle part of the posterior surface of the medulla is occupied by the 
posterior pyramids, which are placed one on each side of its posterior 
median fissure, and which are continuous behind with the median 
dorsal parts of the spinal cord, and in front seem to blend with the 
restiform bodies. 

In order to see the inferior, or ventral, surface of the brain, it 
must be removed from the cranial cavity, the cerebro-spinal axis 
being cut through at the foramen magnum, i.e., at the hinder end of 
the medulla oblongata. This being done, the cut surface of the 
medulla will exhibit a doubly crescentic arrangement of internally 
placed grey tissue, similar to that shown by the cut surface of the 
spinal cord. If, however, sections of the medulla be made at points 
further and further forwards, it will be seen that the grey matter 
gradually becomes concentrated (as the medulla advances forwards) 
near the middle of its dorsal surface. 

The ventral surface of the brain being in view, the two lateral 
parts of the cerebellum are visible, one on each side of the medulla — a 
small process of each half — called the floculas — is connected by the 
dura mater with that depression on the inner surface of the petrous 
portion of the temporal bone, which was described as the cerebellar 
fossa.* Continuing on we find on each side of the anterior end of 
the anterior pyramids a conspicuous band of transverse fibres, each 
of which is called a corpus trapezoideum. Immediately in front of 
these bands, is the transverse, convex eminence of the pons Varolii, 
against the hinder margin of which the front ends of the anterior 
pyramids abut. The corpora trapezoidea form a transverse band 
which is interrupted by these pyramids, while the greater band of the 
pons Varolii is uninterrupted by them. The pons lies upon the anterior 
part of the basi-occipital bone, and is medianly grooved by an antero- 
posterior shallow depression, along which runs the basilar artery. 

Emerging from the front of the pons are two masses of white sub- 
stances marked with longitudinal striae, and made up of longitudinal 
fibres (the crura cerebri) which diverge as they advance, and are 
crossed superficially by two anteriorly converging round cords, the 
optic tracts (which unite to form the optic nerves), and thus a 
lozenge-shaped space is enclosed. At their opposite extremities the 
optic tracts run upwards and backwards to the corpora geniculata 
already noticed. In the hinder part of this space (called inter- 
peduncular) is a small rounded mass, the corpus albicans, which shows 
an indication of a median division into two lateral halves termed 
corpora mammiUaria. In front of this is a slight prominence termed 
the tuber cinereum, from the middle of which projects a hollow 

* See ante, p. 66. 



264 



THE CAT. 



[CHAP. IX. 




conical process, the infundibulum. At the end of the infundibulum 
is a small oval reddish mass called the pituitary body, which is 

received into the pituitary fossa 
(or sella turcica) of the sphenoid 
bone. 

Between the diverging crura 
and the corpus albicans, is a 
depressed surface of greyish 
matter perforated by numerous 
small vascular openings, whence 
it is termed the locus perforatum 
posterior. 

The tuber cinereum is a 
lamina of grey nervous matter 
extending forwards from the 
corpus albicans to the median 
junction of the optic tracts, or 
optic commissure. 

The pituitary body is very 
vascular, and in structure is 
like a ductless gland, consisting 
as it does of connective tissue 
with granular matter and nu- 
cleated cells. 

Another grey space with 
vascular openings — called the , 
locus perforatum anterior — is 
placed on each side just in 
front of each optic tract. 

Anterior to and beside these 
small median parts are those 
voluminous masses the cerebral 
hemispheres, which thus form 
a very large part of even the 
under surface of the brain. 

The great longitudinal fissure 
is seen m the middle line in 
front, and another but small 
(Figs 125) lateral fissure (called 
the Sylvian fissure) separates 
the anterior (or frontal) lobe from the one behind (or temporal 
lobe) of the same hemisphere. The temporal lobes form two 
great prominences on each side of the brain's under surface. 
Each is bounded behind by the cerebellum, and is well marked 
off in front by the Sylvian fissure. 

In a groove on the under surface of each frontal lobe is a body, 
shaped something like a life-preserver, with an oblong head and a 
thick stalk. This is the olfactory lobe or bulb. It is made up 
largely of grey matter, but also contains white fibres. The stalks 



Fig. 128.— Base of the Brain. 

F. Frontal lobe. 
T. Temporal lobe. 
ol. Olfactory lobe. 
m. Medulla oblongata. 

cb. Cerebellum. 

p. Pituitary body. 
pv. Pons Varolii. 

cc. Crura cerebri. 
s. Sylvian fissure. 

mm. Corpora mammillaria or corpus albicans. 

Ip. Locus perforatus anterior. 

ct. Corpus trapezoideum. 

pa. Anterior pyramid. 

J. Source of olfactory nerves. 

II. Optic nerve. 

III, IV, VI. 3rd, 4th, and 6th nerves (those of 
eye-muscles). 

V. Trigeminal nerve. 
VIT. Facial nerve. 

VIII. Auditory nerve. 

IX. Glossopharyngeal. 

X. Pneumogastric. 

XI. Spinal accessory. 

XII. Hypo-glossal. 



chap. ix.J NERVOUS SYSTEM AND ORGANS OF SENSE. 265 

connecting the lobes with the under surface of the cerebrum are the 
crura, or peduncles of the olfactory lobes. 

Upon turning back the optic tracts — at their union in the optic 
commissure— & delicate layer is seen to connect them with the 
anterior end of the corpus callosum. This delicate layer is called 
the lamtna cinerea, or lamina terminalis. It is also continuous, 
below the optic commissure, with the tuber cinereum, and it is con- 
nected on each side with the locus perforatus anterior. 

As has been said, the minute cavity of the spinal cord expands 
within the brain into a series of chambers, filled with fluid, termed 
" ventricles." 

The hindmost or fourth ventricle is placed between the cerebellum 
and the medulla oblongata. It is a flattened, somewhat rhomboidal 
space, bounded on each side by the crura of the cerebellum. Its 
floor is formed by the posterior (dorsal) surface of tbe medulla. Its 
roof is formed by the cerebellum and by the very delicate layer of 
nervous raattei placed between the processus a cerebello ad 
testes, and already spoken of as the valve of Yieussens. It is also 
bounded by a still more delicate film of nervous substance which 
extends backwards from the cerebellum between its posterior (or 
inferior) crura, the restiform tracts. 

This ventricle is prolonged onwards by a narrow passage into a 
larger cavity, the third ventricle, from the anterior wall of which a 
small aperture leads right and left into two lateral ventricles (one on 
each hemisphere,) each of which is still further continued on into 
the olfactory lobe in front of it. The further relations of the 
various parts will be best understood by studying a median, 
vertical anteroposterior section of the brain. 

If the brain be thus bisected in the line of the longitudinal 
fissure, we find as follows : — 

The inner surface of the cerebral hemisphere in view is convo- 
luted, and the cerebrunrjnay be seen to extend forwards together 
with and above the olfactory lobe in front, and beyond the anterior 
end of tbe cerebellum behind 

Beneath the middle of the cerebrum we come to the cut surface 
of the corpus callosum, the front part of which bends rather sharply 
backwards and downwards, forming what is called the knee (genu). 
Beneath the bent-back extremity of the corpus callosum is the cut 
edge of the lamina cinerea (or terminalis). At the upper part of this 
lamina we find the cut surface of a transversely- extending white 
cord, called the anterior commissure, and immediately behind the 
lamina we find another cord, part of what is called tine fornix. This 
latter structure extends, not transversely, but at first upwards and 
forwards ; afterwards curving backwards it passes to the hinder part 
of the corpus callosum. The fornix is the median part of what is 
really and morphologically the back of the cerebral hemispheres, 
each half of the fornix belonging to one of the hemispheres. The 
layer joining the two diverging and posterior portions of the 
fornix is called the lyra, and together these parts form part of the 



2C6 



THE CAT. 



[CHAP. IX. 



outer wall or bag of the cerebrum enclosing the lateral ventricles. 
Filling up the interval between the corpus callosum and fornix is a 
double membrane called the septum lucidum, a space called the fifth 
ventricle being included between its two layers. 

Below the fornix we have evidently cut into a cavity extending 
down into the infundibulum and bounded in front by the lamina 
terminalis. This cavity is called the third ventricle. A small 
aperture (the foramen of Monro) opens immediately behind the 




Fig. 129.— The Brain, as seen when a vertical longitudinal section has been 

MADE THROUGH ITS MIDDLE. 



etc. Anterior commissure. 

av. Arbor vitse of cerebellum. 

c. Crucial sulcus. 

cm. Corpus albicans. 

cc. Corpus callosum. 

cq. Corpora quadrigemina. 

F. Frontal lobe of cerebrum. 

/. Fornix. 

fm. Foramen of Monro (between the fornix and 
the corpus callosum is the fifth ventricle, 
enclosed by the two vertical layers of the 
septum lucidum, which pass from the lornix 
to the corpus callosum). 

Ji. Hippocampal gyrus. 

r iii. Medulla oblongata. 

ol. Olfactory lobe. 



pv. Pons Varolii. 

p. Pineal gland. 

pt. Pituitary body. 

s. Superior external gyrus. 

v. Velum interpositum (between it and the fornix 
is a space enclosed by the folding over of 
the cerebrum upon the roof of the third 
ventricle). 

3. Third ventricle. 

4. Anterior end of fourth ventricle. 

II. Optic nerve, which leads back to the fourth 
ventricle beneath the cerebellum. 

The large white spot above Fig. 3 is the middle, 
or soft commissure, cut across. The white 
spot beneath and in front of Fig. 3 is the 
cut surface of the optic chiasma. 



anterior part of the fornix, and a little behind this aperture is the 
cut edge of a bundle of transverse fibres which form what is called 
the soft (or middle) commissure. The third ventricle is bounded 
above by a delicate membrane, the velum interpositum, which 
consists only of the ependyma, the pia mater, and the arachnoid. Its 
margins are very vascular, and bear the name of the choroid plexuses. 
The vascularity is continued on in that part of the ependyma which 
passes through the foramen of Monro into the lateral ventricles, 
but of course the pia mater and arachnoid do not pass through that 
foramen, as they never get inside the ventricles at all, but are 
reflected back on the under surface of the fornix. Thus the 
" choroid plexuses " of the lateral ventricles are (like those of the 
third) merely portions of the ependyma, which happen to be very 
vascular, and are not really intrusions from without. 1 his velum 
interpositum thickens behind and forms a small prominence which 
projects backwards as the pineal gland — reminding us of the pituitary 
body below. It is reddish and very vascular, and contains two or 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 267 

more cavities filled with a viscid fluid and gritty matter formed 
of earthy salts. The third ventricle is bounded interiorly by the 
corpus albicans and crura cerebri and by the infundibulum, into 
which it extends. 

The space between the upper surface of the velum and the under 
surface of the closely applied lyra is morphologically the outside of 
the brain, though, in fact, it is in the middle of the eomplex whole 
of the adult structure. 

The cavity just described, the third ventricle, continues on back- 
wards as a very narrow passage (the iter a tertio ad quartum ventri- 
culum), bounded below by the crura cerebri and above by a layer 
of nervous matter continuous w r ith the pineal gland, and exhibiting 
the cut surface of a small transverse cord (the posterior commissure), 
and also two prominences in section — parts of the corpora quadrige- 
mina. A little further back, tbis passage expands into the fourth 
•ventricle bounded in the way as already described. 

The cerebellum in section shows (as might be expected from what 
has been said about its structure) radiating, tree-like ramifications 
of nervous substance (grey and white) known as the arbor vitce. 

Other sections are necessary to make clear other matters. Thus, 
the foramen of Monro is the entrance to a cavity which is placed in 
the cerebral hemisphere of the same side, these two cavities con- 
stituting the first and second (or two lateral) ventricles. 

The so-called foramen of Monro is, in fact, a Y-shaped passage. 
It is single below, where it communicates with the third ventricle, 
but divides above into two branches, one to each lateral ventricle. 

Each lateral ventricle is said to have two cornua. The anterior 
cornu passes into the frontal lobe and penetrates the olfactory lobe 
also. The posterior or descending cornu passes into the temporal 
lobe. Certain sulci on the surface of the cerebrum extend so deeply 
as to produce eminences on the inner surface of the lateral ventricles. 
One such structure in the descending cornu has been termed the 
hippocampus major, and is a very marked elongated and rounded 
prominence. 

Each central hemisphere is, in fact, a bag, with walls of very 
unequal thickness. Thus, part of the inner wall running along the 
descending cornu of the lateral ventricle is reduced to the ependyma 
(with the pia mater and arachnoid), and readily tears (forming what 
is called the fissure of Bichat), and this rupture having (in man) 
been mistaken for a natural opening, each lateral ventricle has been 
supposed to communicate with the exterior close to the crus cerebri. 

The hindmost part of the roof of the fourth ventricle is formed of 
the ependyma alone, the pia mater and arachnoid being reflected 
over the postero-inferior surface of the cerebellum. 

Careful inspection shows that the septum lucidum is really (as 
already mentioned) double, enclosing a very narrow space — the fifth 
ventricle — the laminae of the septum lucidum passing downwards 
from the corpus callosum to the fornix. This fifth ventricle has no 
connexion with the other ventricles, and it differs from them, not 



268 THE CAT. [chap. ix. 

only in its isolation, but in its nature. It is in no way a prolonga- 
tion forwards of the spinal canalis centralis. 

This fornix is made up of two white cords closely approximated 
anteriorly and diverging widely behind. Each springs from the 
corpus albicans, and the two cords (called pillars or crura) ascend 
(side by side) behind the anterior commissure, and with a branch of 
the foramen of Monro on the outer side of each. They then curve 
backwards, diverging, but at the same time united by that delicate 
membrane called the lyra. They become connected with the corpus 
callosum, and then pass into each descending cornu of the lateral 
ventricles. 

Two rounded bodies (the optic thalami) are placed one on each 
side of the first described cavity (the third ventricle), and are con- 
nected by the soft (or middle) and posterior commissures. Two 
other rounded bodies (the corpora striata) are placed one in etfch 
cerebral hemisphere between the anterior and descending cornua. 
They are connected by the anterior commissure, which (like the 
posterior commissure) is formed of white, transverse fibres, while the 
soft commissure is almost entirely composed of grey matter. 

Each corpus striatum is an outgrowth from the middle of the base 
of its hemisphere, and is the morphological axis of the whole 
hemisphere. 

The optic thalami are thickenings in the outer wall of the third 
ventricle. 

The two cords which have been spoken of as the optic tracts, 
arise, one on each side, from the optic thalami and run forwards 
obliquely across the under surface of the brain to join together 
immediately in front of the infundibulum. 

We have seen that the two sides of the brain are connected by 
the fibres of the corpus callosum and of the three smaller commis- 
sures. There is not only this direct transverse connection. Oblique 
extensions of fibres also connect the right hemisphere with the left 
side of the spinal cord (and therefore with the left side of the body), 
and the left hemisphere with the right half of the spinal cord (and 
therefore with the right side of the body). The fibres which pass 
forwards through the " anterior pyramids " decussate and then 
extend through the crura cerebri to the cerebrum. The fibres of 
the crura radiate within the cerebrum in a fan-like manner, the 
corpus striatum and thalamus being respectively anterior and 
posterior to such radiation. 

The transverse relation which thus exists between the two sides 
of the brain and the body (which it supplies with nerves) extends 
also to the organs of sight, but not to that of smell. 

"We may now, in conclusion, review the conditions presented by 
the cerebral convolutions, i.e., by the gyri and sulci of the cerebrum. 
These are thus disposed as follows : — 

On the upper surface of the brain three more or less parallel 
prominences or gyri, extend antero-posteriorly on each side of the 
median longitudinal fissure. The innermost of these, the superior 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 269 

lateral gyrus (Figs. 125 and 126, s) runs straight from behind for- 
wards till it comes to a transverse furrow, the crucial sulcus (c), 
round which it bends, running inwards again, and finally turns 
outwards and downwards round another sulcus called the supra- 
orbital (o). The next gyrus is the middle lateral (m)> which curves 
outwards and downwards at each end. Finally comes the inferior 
lateral gyrus (i), which is seen, in this view, to be somewhat divided 
towards each end by the terminations of two ascending sulci. 

"When the brain is vertically bisected, we see, above, the superior 
lateral gyrus traversed by a feebly indicated antero- posterior groove, 
while a deep sulcus, the calloso-marginal sulcus, divides it incom- 
pletely from the hippocampal gyrus (Fig. 129, h), which immediately 
adjoins the corpus callosum, behind which it dips down, and passing 
round the crus cerebri of that side runs forwards the marked promi- 
nence of the temporal lobe (Fig. 128, h). The sulcus on the concave 
side of the lower part of this gyrus forms (by projecting into the 
descending cornu of the lateral hemisphere) the hippocampus major, 
which circumstance gives its name to this gyrus. At the anterior 
end we see the crucial sulcus (Fig. 129, c), with the internal surface 
of the superior lateral gyrus beneath it. 

When the brain is seen in profile, we see at its anterior end the 
sharp bend upwards and downwards of the superior lateral gyrus 
around the supra-orbital sulcus (Fig. 125, o) and then its ascent 
behind the crucial sulcus (c) ; after w T hich it runs back along the 
summit of the hemisphere. Within this is the median lateral fold (m), 
while the whole space embraced by it is occupied by the inferior 
lateral gyrus traversed by two ascending sulci, the summits of which 
sulci appear at the side of the upper view of the brain. Next to 
be noted is the small but very important Sylvian fissure (s), which 
forms as it were the axis round which all these convolutions are 
disposed. Finally the anterior end of the hippocampal gyrus (h) 
makes its appearance beneath and in front of the Sylvian fissure. 

When the under surface of the brain is in view we see the lower 
anterior ends of the three lateral gyri, and the large expanded 
termination of the hippocampal gyrus is the temporal lobe. 

§ 8. Having now reviewed the nervous centres or cerebrospinal 
axis, we may proceed to consider the peripheral part of the 
nervous system, i.e., the nerves which are given off by the axial part 
of that system. 

The nerves which go forth from the cerebro- spinal axis to different 
parts of the body are bilaterally symmetrical, there being (beyond 
the olfactory nerves) a pair (one right and one left) of each. 

The most anteriorly -situated nerves attain their destination after 
passing through the foramina of the skull, on which account they 
are denominated cranial nerves. 

Of these there are twelve, as follows : — 

1. Olfactory. 

2. Optic. 

3. Oculo-motor. 



270 1HE CAT. [chap. ix. 

4. Pathetic (or trochlear). 

5. Tri-geminal. 

6. Abducent ocular. 

7. Facial 

8. Auditory. 

9. Glosso-pharyngeal. 

10. Pneumogastric. 

11. Spinal accessory. 

12. Hypo-glossal. 

Some anatomists reckon but nine cranial nerves ; for they count 
the eighth as one with the seventh (calling the facial part its portio 
dura, and its auditory part its portio mollis), and reckon the 
glosso-pharyngeal, pneumogastric, and spinal accessory (all taken 
together), as their eighth. According to this latter system, the 
hypoglossal nerve becomes the ninth. 

The cranial nerves generally are said to have two kinds of roots 
or origins, one deep, the other superficial ; . but these are but different 
portions, or stages, of the same nervous cord. The superficial 
origin of each nerve is the point where it is obviously attached to 
the surface of the encephilon, while its deep (or real) origin in- 
dicates the furthest point to which it has yet been traced backwards. 
A nerve may be visibly attached to the encephalon by one or several 
roots. Some of these nerves are what is called " sensory," and others 
" motor/' according as they minister to sensation or to motion. 

§ 9. The first, or olfactory nerves, are the numerous delicate 
fibres which pass from the under surface of the olfactory lobes, 
through the holes in the cribriform plate, down to the membrane 
investing the nasal septum and ethmo-turbinals. What are, 
however, often spoken of as the " olfactory nerves " are the olfactory 
bulbs themselves, with the stalks, or peduncles, which connect them 
with the under surface of the cerebrum. 

They are composed of grey matter mixed with white fibres, the 
grey matter being especially abundant in the bulb. Each so-called 
nerve has at least two roots : — 

1. The external root is a broad band of white fibres, extending 
outwards and backwards along the outer margin of the anterior 
perforated space to the Sylvian fissure (Fig. 128). 

2. The inner root consists of a narrow band of white fibres, which 
extends back along the inner side of the anterior perforated 
space. 

§ 10. The second, or optic, pair of nerves spring superficially 
from the union of the optic tracts, in what is called the chiasma or 
optic commissure (Fig. 128). 

Their deep origin may be traced back to the optic thalami, corpora 
geniculata, and corpora quadrigemina. Fibres arising from these 
parts converge on each side, and form the optic tract, which runs 
obliquely across the lower surface of the crus cerebri of the same 
side, behind the anterior perforated space to the chiasma. Posteriorly, 
it is more flattened ; anteriorly, it is more cylindrical. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 271 

Arrived at the chiasma, the outer fibres of each tract continue 
onwards to the optic nerve of the same side beyond the chiasma, 
while the inner fibres cross over in the chiasma, and continue on in 
the optic nerve of the opposite side. Some fibres appear to cross 
from one optic tract to another, along the posterior part of the 
chiasma, and others to cross, along its anterior part, from one optic 
nerve to another. 

From the chiasma each optic nerve extends through the optic 
foramen in front of it — diverging widely from its fellow of the 
opposite side. Emerging from the optic foramen, it is surrounded 
by the recti muscles of the eyeball, the hinder part of which it 
enters a little to the inside of its middle, piercing the two outer 
coats of the eyeball, and expanding within it (to form the Retina), 
as will be hereafter noticed in describing the eye. 

The optic nerve is made up of a number of separate bundles of 
fibres, enclosed in prolongations of the dura mater. In the middle 
of these bundles runs a small artery called the arteria centralis retinae. 
§ 11. The third pair of nerves (oculo-motor) arise deeply from a 
grey nucleus in the floor of the iter a tertio ad quartum ventri- 
culum, close to the origin of the fourth nerve. They issue from the 
cerebral surface in the interpeduncular space between the 
crura and cerebri, and immediately in front of the pons Varolii 
(Fig. 128, III). 

Each nerve traverses the dura mater and sphenoidal fissure, and, 
after receiving one or two fine branches from the sympathetic, 
divides, and goes to supply the superior, inferior, and internal recti 
muscles of the eyeball, as also its inferior oblique muscle, and that 
of the elevator of the eyelid. 

The fourth pair of nerves, called also the trochlear or (from 
their function of raising the eyeball) pathetic, arise deeply from 
one grey nucleus in the floor of the iter a tertio ad quartum ventri- 
culum, and from another in the floor of the fourth ventricle — close to 
the origin of the fifth nerve. They issue from the cerebral surface, one 
on the outer side of each of the crura cerebri (Fig. 128, IV), im- 
mediately in front of the pons, but each may be traced back round 
the eras to a spot below and behind the corpora quadrigemina in 
the valve of Yieussens. It goes through the sphenoidal fissure to 
the upper oblique muscle of the orbit. 

§ 12. The fifth pair of nerves, called also the trigeminal, 
arise by two roots, one large sensory root, and one small root called 
motor, because its branches minister not to sensation, but to 
muscular contraction. 

The large root takes its deep origin from behind the olivary body, 
if not from the floor of the fourth ventricle, and emerges from the 
surface of the encephalon at the side of the pons Varolii, near its 
upper and anterior margin, just where its fibres extend upwards 
and backwards to form the middle crus of the cerebellum. 

The small root also takes its deep origin from the medulla 
oblongata, and possibly from the floor of the fourth ventricle. It 



27*2 



THE CAT. 



CHAP. IX. 



comes to the surface of the encephalon just above the superficial 
origin of the larger root, which at first conceals it. 

At a short distance from its origin the larger root swells out into 




Fig. 130. — Diagram representing the principal Cranial Nerves. 



The orbit is cut open, the zygoma and part 
of the cranial wall removed, and the man- 
dible reflected downwards to show its inner 
surface. 

MN. Third or nictitating eyelid. 

Sr. Superior rectus muscle. 

Er. External rectus. 

Ir. Infeiior rectus. 

Lp. Levator palpebrse muscle, cut and pulled 
upwards. 

gn. Gustatory nerve, going to tongue. 

Ct. Chorda-tympani. 

in.d. Inferior dental. 

trill. Mylo-hyoid. 

Oc. Occipital condyle. 

i. Infra-orbital. 



d. Dental nerve. 

gg. Gasserian ganglion. 

gpv. Ganglion of trunk of pneumogastric. 

si and il. Superior and inferior laryngeal nerves. 

2. Optic nerve. 

3. Third nerve, or ocido-motor. 

5. Trigeminal. 

ha. Ophthalmic, or first division of fifth nerve. 
55. Its second division. 
5c. Its third division. 

6. Sixth nerve, or vbducens. 

7. Facial. 

9. Glossopharyngeal. 

10. Pneumogastric. 

11 . Spinal accessory. 

12. Hypo-glossal. 



what is called the Gasserian ganglion (Fig. 130, gg). It is joined 
hy some sympathetic nervous filaments, and then gives off three 
large branches, the hindmost of which is joined by the fifth nerve's 
lesser root. 

The first of these three branches, which is the smallest, and 
one notably distinct from the others, is called the ophthalmic 
n£rve (Fig. 130, 5a), which passes through the sphenoidal fissure, 
and supplies, by its subdivisions, the eyeball, mucous membrane of 
the eyelids, lachrymal gland, and the skin of the nose, forehead, 
and upper eyelid, dividing into its nasal, frontal, and lachrymal 
branches. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 273 

The second of the three branches of the fifth nerve is called the 
superior maxillary nerve. It passes through the foramen 
rotundmn, and supplies the lower eyelid, the side of the nose, the 
upper teeth, and the upper part of the mouth and pharynx. After 
issuing through the foramen rotundum, the nerve crosses to the 
infra-orbital canal (Fig. 130, 5b), which it traverses, and then 
divides and goes to the parts adjacent. The anterior and posterior 
dental branches supply the teeth. 

Connected with this nerve is a structure called the spheno- 
palatine ganglion — or Meckel's ganglion — which is placed outside the 
spheno-palatine foramen. 

The third branch of the trigeminal (Fig. 130, 5c), which is 
the largest branch, is termed the inferior maxillary nerve. It 
passes through the foramen ovale, and supplies the ear, side of the 
head, lower lip, gums, teeth, salivary glands, and inside of the mouth. 
As has been said, it is this part with which the smaller, or motor, 
root of the trigeminal alone unites. After such union, which 
takes place just outside the foramen ovale, it subdivides into two 
poitions. The smaller of these (which conveys a motor influence 
alone) goes to the masticatory muscles ; the larger again subdivides 
into three nerves. 

The first of these, the auricido-temporal nerve, passes backwards, 
under the external pterygoid muscle, and then upwards between the 
mandible and the external meatus, underneath the parotid gland. 
There it divides, and its ramifications extend up in the temporal region. 
The second, or gustatory nerve (Fig. 130, gn), which ministers to 
taste, descends beneath the pterygoid muscles to the side of the 
tongue, passing above the deep part of the submaxillary gland and 
crossing Wharton's duct. 

In the early part of its course this nerve is joined by a slender 
branch from the seventh nerve, called the chorda tympani (Fig. 
130, Ct). m 

The third, or inferior dental nerve (which is the largest of the 
divisions of the third branch of the trigeminal), descends outside 
the gustatory nerve and enters the inferior dental canal and supplies 
the lower teeth (Fig. 130, in.d). 

Before entering the canal it gives off the mylo-liyoid branch 
{mh), which runs down the inside of the mandible to the mylo- 
hyoid and digastric muscles. 

A branch of the inferior dental foramen escapes outwards at the 
mental foramen and supplies the adjacent muscles. 

§ 13. The sixth nerve (Figs. 128 & 130, 6 ), called also the 
abducens, seems again to take its origin from the floor of the fourth 
ventricle. It comes to the surface at the hinder margin of the pons 
Varolii, between that margin and the anterior pyramid and olivary 
body of the same side of the medulla oblongata. 

The nerve passes forwards and enters the orbit through the 
sphenoidal fissure, and is distributed to the external rectus and the 
choanoid muscles of the eyeball. 



274 THE CAT. Tchap. ix. 

The seventh, or facial nerve (called also the portio dura, when 
reckoned as one with the anditory nerve) has its deep origin in the 
medulla oblongata between the restiform and olivary bodies, and 
perhaps from the outer wall of the fourth ventricle. 

It comes to the surface from the corpus trapezoideum (Fig. 128, 
VII.) just outside and slightly behind the origin of the sixth nerve. 
Entering the meatus auditorius interims, it proceeds through the 
aqueduct of Fallopius, and emerging at the stylo-mastoid foramen 
(Fig. 130, 7 ), penetrates the parotid gland, when it divides (behind 
the mandible) into two branches, the subdivisions of which ramify 
over the side of the head, face and neck, going to the muscles 
of the ear, scalp, mouth, nose, and eyelids, and also to the platysma 
myoides (Fig. 88, n). 

Near its exit from the aqueduct it gives off a slender branch, 
called the chorda iympaiii, which enters the hinder part of the 
tympanic cavity (by a canal opening close to the bony frame of the 
tympanic membrane), crosses that membrane and that process of 
the malleus which is called the manubrium,* and finally escapes 
through the fissura Glaseri to join the gustatory nerve — as already 
mentioned. 

§ 14. The eighth, or auditory nerve (called also the portio mollis, 
when reckoned as one with the auditory nerve), has its deep origin in 
the floor of the fourth ventricle. It also receives accessions by fibres 
from the restiform body and, perhaps, also from the pons. It emerges 
from the surface of the encephalon behind the pons, from the corpus 
trapezoideum (Fig. 128, VIII), just behind and external to the 
emergence of the seventh nerve. It enters the meatus auditorius 
internus along with the seventh nerve, and bifurcates at the end of 
that canal, one part going through the anterior part of the cribriform 
lamina to the cochlea and the other through its hinder part to the 
vestibule, as described in treating of the organ of hearing. 

§ 15. The ninth, or glosso -pharyngeal nerve (Figs. 128, IX., and 
130, 9 ), has its deep origin in the grey matter of the posterior part 
of the medulla oblongata. It quits the surface of the encephalon 
just behind (and below) the origin of the seventh nerve, emerging 
behind the upper part of the olivary body and superficially connected 
with the restiform body. It quits the skull by the jugular foramen, 
and then descends between the carotid artery and the jugular vein, 
but turns forwards and inwards at the lower border of the stylo- 
pharyngeus muscle, and goes to the tongue, passing under the 
hyoglossus muscle and being distributed to that organ and to the 
tonsil and pharynx. 

The tenth, or pneumogastric nerve (Figs. 128, X., and 130, 10 ), 
called also the par vagum, is the longest of all the, nerves of the 
encephalon, extending downwards as far as the stomach. Its deep 
origin is situated in the grey nuclei of the hinder part of the medulla 

* For the explanation of these terms, see the description of the internal ear, 
infra, p. 298. 



chap, ix.] NERVOUS SYSTEM AXD ORGANS OF SENSE. 275 

oblongata, nearer the middle line than the origin of the ninth nerve. 
Superficially it arises from the restiform body, close to and immedi- 
ately below the ninth nerve, and springs from a considerable number 
of roots— in a series one below another, forming a_ flat fasciculus. 
It passes out of the jugular foramen beside the ninth nerve. It 
developes two ganglia ; one near its root and one (Fig. 130, gpv) 
on its trunk. 

It then descends the neck between the internal jugular vein and 
carotid artery and passes into the thorax above the innominate vein 
and root of the lung, whence it passes down the oesophagus, in the 
posterior mediastinum, to the stomach. 

Pharyngeal and laryngeal branches go to the pharynx and larynx 
respectively. 

Cardiac branches pass down to the heart, both from the cervical 
and thoracic parts of the nerve. 

Pulmonary branches are given off to the lungs, the largest ones 
being those which pass to those organs on the hinder aspect of the 
lun£ root. 

The oesophagus also receives branches from the pneumogastric, 
termed oesophageal, on both sides of the lung root. 

The nerve ends in its gastric branches. The left pneumogastric 
passes backwards on the ventral aspect of the oesophagus and is 
distributed over the ventral side of the stomach (some fibres going 
to the liver) while the right pneumogastric descends on the dorsal 
aspect of the oesophagus and is distributed over the dorsal side of 
the stomach — some fibres going to the spleen. 

The eleventh, or spinal accessory nerve (Figs. 128, XL, and 
130, n ), is a comparatively insignificant one. It takes origin lower 
down than any other nerve reckoned as belonging to the encephalon, 
namely, below the foramen magnum, from the side of the myelon, 
by a series of delicate roots. Ascending into the skull through the 
great occipital foramen, it passes out again through the jugular 
foramen, in two divisions. One division is completely united with 
the pneumogastric — the union commencing at the ganglion of the 
root of that nerve and being completed below the ganglion of its 
trunk. The other division turns backwards and supplies the sterno- 
mastoid and trapezius muscles. 

The twelfth, or hypoglossal nerve (Figs. 128, XII., and 130, 12 ), 
is the nerve of the muscles of the larynx and hyoid, including the 
tongue, to which it conveys motor impulses. Its deep origin is in the 
grey matter of the posterior part of the medulla oblongata, close to 
the posterior fissure. Its fibres are said to undergo a partial decussa- 
tion in the floor of the fourth ventricle. It quits the encephalon by 
scattered roots which corae forth between the anterior pyramid and 
the olivary body in a line with what we shall find to be the anterior 
roots of the spinal nerves situated below. The roots collect and pass 
through the anterior condyloid foramen. Thence the nerve descends 
to the inferior margin of the digastric and then turns forwards and 
runs, above the hyoid, to the'under part of the tongue. 

t 2 



276 THE CAT. [chap. ix. 

§ 16. Here it may be well to present a preliminary summary of 
the nerves of the encephalon with respect to their functions, although 
the functions of the nervous system and of its main divisions will be 
described more fully later. 

The twelve nerves just enumerated may be divided into three 
categories : (A.) Those which minister to special sense ; (B.) those 
which are motor, and (C.) those which minister both to common 
sensation and to motion. 

The nerves which minister to special sensation are the first, 
second, eighth, the gustatory branch of the fifth, and the tongue 
branches of the glosso-pharyngeal. 

The third, fourth, sixth, seventh,, and. twelfth, are motor nerves. 
The fifth, glosso-pharyngeal, pneumogastric, and spinal accessory 
nerves are all both motor and sensory, though the glosso-pharyngeal 
is mainly sensory. 

§ 17. The spinal nerves arise systematically, in pairs, from 
opposite sides of the spinal marrow. They are related in number to 
the divisions of the axial skeleton, or vertebrae, and (as has been 
said in describing that skeleton) they pass out of the neural canal 
in the intervals between the neural arches. They are severally 
reckoned as cervical, dorsal, lumbar, sacral, or caudal, according to 
their proximity to similarly named vertebrae, each nerve taking the 
name of that vertebra which forms the anterior boundary of its place 
of exit. Thus, inasmuch as one spinal nerve comes out above (in 
front of) the atlas, there are eight cervical nerves, thirteen dorsal, 
seven lumbar, and three sacral, while the rest are caudal. 

The spinal nerves each arise by two roots, and each, after leaving 
the neural vertebral canal, divides into two conspicuous branches 
(one dorsal and the other ventral), besides sending a twig to the 
sympathetic. 

Of these two series of conspicuous branches it is the ventral series 
which constitutes* the nerves of the limbs, while, in the interval 
between the limbs, the ventral branches pass round in the body wall 
— the thoracic ones in the intercostal spaces, and the abdominal ones 
between the internal oblique and trans versalis muscles, as will be 
shortly described. 

The roots by which each spinal nerve arises are (as has been 
said) two in number : one anterior (ventral), and the other posterior 
(dorsal), and each is made up of a number of small bundles (funi- 
culi) of nerve-fibres. 

The funiculi of the posterior (dorsal) root come forth from the 
posterior lateral furrow. They are larger and more numerous than 
are the funiculi of the anterior root. Within the substance of the cord 
the fibres of the posterior — or dorsal — root of each nerve may be traced 
diverging in three directions, namely, postaxially, or away from the 
brain, preaxially, or towards the brain, and transversely across. The 
first pass along the grey matter to the anterior cornu and anterior 
white columns. The second advance through the grey matter to the 
posterior columns. The third (transverse fibres) enter the posterior 



chap, ix.] NERVOUS FYSTEM AND ORGANS OF SENSE. 277 

cornu, and some cross the posterior commissure and reach the 
posterior and lateral columns of the opposite side. 

The funiculi of the anterior (ventral) root pass straight to the 
anterior cornu and there also diverge postaxially, preaxially, and 
horizontally. 

The funiculi of the posterior (dorsal) root unite to form a single 
cord, which is furnished with an oval mass of grey matter, or 
ganglion, varying in size with the size of the nerve. 

The funiculi of the anterior (ventral) root unite together without 
developing any ganglion, and the cord so formed unites with that 
from the posterior root beyond (i.e., distally to) the ganglion. 

Each spinal nerve having thus been formed by the union of its 
roots, divides (as before said) into two conspicuous branches termed 
its dorsal and ventral primary divisions. Fibres from each of 
the two roots are so blended in the part where the nerve is single, that 
after its division each of its two parts contain fibres derived from both 
the anterior (ventral) and posterior (dorsal) root of the nerve. 

The dorsal primary divisioxs of the spinal nerves are dis- 
tributed to the muscles and skin of the dorsal region, and divide into 
internal and external branches. 

The cervical internal branches pass upwards in the vicinity of the 
neural arches. The external branches pass outwards, and supply 
the cervical prolongations of the erector spina?. 

The dorsal internal branches proceed between the multifidus 
spina?, and either the semi-spinalis dorsi or the longissimus dorsi — 
therefore in the vicinity of the neural arches. Their external 
branches (which become bigger from before backwards) pass be- 
neath the longissimus dorsi to the interval between it and the 
sacro-lumbalis or its continuation forwards. 

The lumbar internal branches pass backwards close to the zyg- 
apophyses into the multifidus spina?, therefore close (once more) to 
the neural arches. Their external branches enter the erector spina?, 
which represents the longissimus dorsi and sacro-lumbalis un- 
differentiated. 

The sacral external and internal branches are distributed in an 
analogous manner. 

The ventral primary divisions of the spinal nerves are dis- 
tributed to the more ventrally situated parts of the body, and they 
are generally a good deal larger than are the dorsal primary divisions. 
They do not divide into an internal and external branch as do the 
dorsal primary divisions of the spinal nerves, but they tend to unite 
together in sundry plexuses, and each gives off a minute branch 
inwards to the sympathetic system, and thus in a certain sense even 
these anterior primary divisions bifurcate ; they bifurcate, namely, 
into a large outer division, and a minute inner one going to the 
sympathetic. 

The ventral primary divisions of the cervical nerves pass out- 
wards between the scaleni and the rectus anticus major muscles. 

The first four or five form an interlacement called the cervical 



278 



TEE CAT. 



[CHAP. IX. 



plexus, placed opposite the first four vertebrae below the sterno- 
mastoid muscle, and connected, near the skull, with the pneumo- 
gastric, hypoglossal, and sympathetic nerves. 

The fifth and sixth cervical nerves give off a branch called the 
phrenic nerve, which passes backAvards between the pleura and the 
pericardium, and is distributed to the diaphragm. 

§ 18. The three posterior cervical nerves unite to form an inter- 
lacement called the brachial plexus, which is of much greater size 

than the cervical plexus, and 
gives origin to the nerves of the 
fore-limb. It is reinforced by 
the first dorsal nerve, and the 
plexus extends down from the 
lower part of the neck to the 
axillary space. 

The connexions formed by the 
nerves in the plexus are some- 
what apt to vary, but the fol- 
lowing conditions appear to be 
normal. A large branch from 
the eighth cervical nerve unites 
with the main branch of the 
first dorsal to form a trunk 
which (after giving off a small 
branch to help to form the me- 
dian) continues on as the ulnar 
nerve (Fig. 131, v). Delicate 
branches from the first dorsal 
and eighth cervical also unite 
to form the internal cutaneous 
nerve (ic). The median nerve is 
formed by the junction of the 
small offshoot from the ulnar 
(already mentioned), with a 
branch from the seventh cer- 
vical nerve. The largest branch 
of the seventh, however, unites 
with a considerable branch from the eighth cervical to form the 
musculo-spiral nerve. From close to the root of the seventh cervical 
the external respiratory nerve of Bell passes backwards. The musculo- 
cutaneous nerve is formed by the junction of slender branches from 
the sixth and seventh cervical nerves, and from the junction of two 
stouter branches from the same two nerves there arise the circumflex 
and the subscapular nerves. Another subscapular nerve is formed 
by the junction of very slender branches from the sixth and seventh 
cervical nerves, while from the sixth there springs a very consider- 
able supra-scapular nerve, and a small branch which goes to the 
rhomboideus muscle. 

The internal cutaneous nerve, as its name implies, passes to ths 




Fig. 131.— Diagram of the Right Brachial 
/ Plexus. 

6C, IC, and 8C. Sixth, seventh, and eighth cer- 
vical nerves. 
ID. First dorsal nerve. 
cf. Circumflex nerve. 
ic. Internal cutaneous nerve. 
m. Median nerve. 
mc. Musculocutaneous nerve. 
ms. Musculo-spiral nerve, 
r. Nerve to rhomboideus muscle. 
rb. Respiratory nerve of Bell. 
sb. Subscapular nerves. 
sps. Supra-scapular nerve. 
v. Ulnar nerve. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 279 

skin of the inner side of the arm. It pierces the fascia and becomes 
cutaneous at about the middle of the inner side of the upper arm, 
and is distributed to both the anterior and posterior surfaces of the 
limb below the elbow. 

The external respiratory verve of Bell, or posterior thoracic nerve, 
at first traverses the scalenus muscle and then passes backwards 
within (i.e., nearer the ribs than) the rest of the brachial plexus to 
the side of the thorax, where it lies upon the serratus muscle, which 
it supplies. 

The supra-scapular nerve passes between the trapezius muscle to 
the dorsal surface of the scapula, and supplies the supra and infra- 
spinatus muscles. 

The subscapular nerves pass to the inner side of the blade-bone, 
and supply the subscapularis, teres major, and latissimus dorsi 
muscles. 

The musculocutaneous nerve descends obliquely through the 
biceps and brachialis anticus muscles to the outer side of the fore- 
limb. It supplies the muscles named as well as the coraco-brachialis, 
and then proceeds to the skin of the outer side of the limb below the 
elbow. 

The ulnar nerve passes down on the inner side of the brachial 
artery to the middle of the upper arm, and then turns backwards to 
between the olecranon and inner condyle, where it is subcutaneous. 
It then descends the lower arm (side by side with the ulnar 
artery), supplying, in its course, the flexor profundus digitorum and 
the flexor carpi ulnaris muscles. Arrived at about the lower third 
of the ulnar artery, it bifurcates into a dorsal and a palmar branch. 
The dorsal branch divides at the carpus into two branchlets, one of 
which runs along the outside of the fifth digit, and the other (after 
receiving a branch from the radial) subdivides and runs along the 
inner side of the fifth, and the outer side of the fourth, digits. The 
palmar branch passes within the pisiforme, and divides into branchlets, 
which go to the muscles of the pollex and fifth digit and to the inter- 
ossei ; another passes along the outside of the fifth digit on its 
palmar aspect ; another similarly supplies the contiguous sides of the 
fourth and fifth digits, and sends a twig to the median nerve. 

The median nerve descends and passes through the internal 
condyloid foramen of the humerus. It then dips below the pronator 
teres, and proceeds amidst the flexor muscles to the wrist ; 
when beneath the annular ligament it divides into three branches. 
On its way it supplies the pronators, the radial carpal flexors, and 
the long flexors of the digits where not supplied by the ulnar 
nerve. Of its three branches, the most internal goes to the pollex 
and the adjacent palmar border of the index digit. The middle 
branch descends into the second interosseous space, and supplies the 
contiguous sides of the index and middle digits. The third branch 
similarly supplies the adjacent sides of the third and fourth digits 
on their palmar aspect. 

The circumflex (or axillary) nerve passes backwards at the 



280 



THE CAT. 



[CHAP. IX. 



lower margin of the subscapular muscle (with the posterior cir- 
cumflex artery) between the scapula and teres major, and goes to 
the deltoid, teres minor, and skin of the shoulder. 

The musculo-spiral nerve is that supplying the supinator and 




Fig. 



132. — Nerves of Right Fore-paw — 
Palmar aspect. 



Median nerve supplying pollex, index, 
medius, and part of annulus, digits. 

Ulnar nerve supplying the minimus and the 
other part of the annulus, digits. 




Fig. 133.— Diagram of the Left Lumbar 
and Sacral Plexuses. 



4Z, 5Z, 6L and 1L. Fourth, 

seventh lumbar nerves. 
15 and 2S. The sacral nerves. 

cc. Anterior crural nerves. 

cd. Caudal nerves. 

ec. External cutaneous nerve. 

gc. Genito-crural nerve. 

gl. Gluteal nerve. 

gs. Great sciatic nerve. 

He. Ilio- hypogastric nerve. 

ill. Ilio-inguinal nerve. 

p. Pudic nerve. 

pz. Nerv i to psoas muscle. 

ss. Small sciatic nerve. 



fifth, sixth, and 



extensor muscles, as well as the skin of the back of the lower part of 
the upper arm, and that of the back of the fore-arm and paw. It takes 
origin above the vessels of the axilla, and passes round the back of 
the humerus to the radial side of the front of the fore- arm, when it 
descends between the supinator longus and the insertion of the 
brachialis anticus, and then divides into the radial and posterior 
inter -osseous nerves. 

The former of these (radial) passes down the fore- arm outside the 
radial artery, and hidden by the supinator longus, till near the wrist, 
where it becomes subcutaneous, and is distributed to the dorsum of 
the pollex, index, and median digits. One branch goes to the pollex 



chap, ix.] NERVOUS SYSTEM AND ORGANS OB SENSE. 281 

and adjacent dorsal border of trie index, and another branch supplies 
the adjacent sides of the index and third digits, and the radial side of 
the fourth digit, also giving off a branchlet to join the dorsal branch 
of the ulnar nerve. 

The posterior interosseous nerve passes through fhe supinator 
brevis to the back of the fore- arm, where it divides, and is dis- 
tributed to the muscles of that region. 

The ventral primary divisions of the dorsal, or thoracic xerves, 
pass out in the intercostal spaces along with the intercostal blood- 
vessels, the last passing along behind the last rib. They soon dip 
between the internal and external intercostal muscles, and each 
gives off a twig to the skin at a point about midway between the 
vertebral column and the sternum. The more posterior of the thoracic 
nerves enter the abdominal wall, and go to the margin of the rectus, 
passing, on their way, between the internal oblique and the trans- 
versalis. They enter the rectus and send small branches to the 
skin. The last dorsal nerve sends back a branch which unites with 
the first lumbar, and so joins in what is called the lumbar plexus. 
Each thoracic spinal nerve sends a short twig, inwards and down- 
wards, to join the sympathetic. 

§ 19. The ventral primary divisions of (h& lumbar xerves are 
larger than those of the dorsal nerves. They severally give off a 
filament to the sympathetic, and then unite in loops to form a 
continuous, complex interlacement of branches, called the lumbar 
and sacral plexuses, whence come the nerves of the hixd-limb. 
The lumbar plexus lies on the ventral aspect of the lumbar transverse 
processes, and is formed by the fourth, fifth, sixth, and seventh lumbar 
nerves. The fourth lumbar nerve, after giving off a branch which 
divides into the iUo-hypogastric and Mo-inguinal nerves (Fig. 133, He 
and Hi), sends a branch backwards, which joins the root of the fifth 
lumbar nerve. From this junction the long genito-crural nerve (gc) is 
given off, and shortly afterwards that called the external cutaneous. The 
trunk then bifurcates, its two branches joining the two branches into 
which the sixth lumbar nerve divides. The larger pair of branches 
thus joining, give origin to the anterior crural nerve (ac), while a 
small twig to the psoas muscle is given off by that root of the 
anterior crural which is contributed by the fifth lumbar nerve. The 
other two branches from the fifth and sixth nerves unite to form a 
branch which gives off the obturator nerve (ob). and then passes 
backwards to join the seventh lumbar nerve, the thick trunk result- 
ing from their junction being called the lumbosacral cord, and con- 
stituting the main root of the great sciatic nerve. 

It is called " lumbo- sacral " because the nerves which come out of 
the anterior sacral foramina are reckoned as forming by themselves 
a sacral plexus, which plexus is placed in communication with the 
lumbar plexus by means of this " lumbo-sacral cord." 

From the outer side of this " cord " the pudic and gluteal nerves 
are given forth. The two sacral nerves unite together — after the 
second sacral has given off some branches to the tail (cd) — to form 



282 THE GAT. [chap. ix. 

a small trunk, which unites with the large lumbosacral cord, and 
forms the great sciatic nerve, the lesser sciatic nerve being given off 
close to the junction of the " small trunk " just mentioned, with the 
lumbo-sacral cord (ss). 

The sacral plexus lies on the ventral surface of the pyriformis 
muscle. 

The ilio-hypogastric nerve comes forth from the anterior part 
of the psoas, pierces the transversalis, and divides — branches coming 
to the surface in the skin of the hinder part of the abdomen. The 
ilio-inguinal nerve follows a very similar course to the last, but is 
distributed to the skin of the groin and external generative organs. 

The genito-crural nerve, which is a very long one, passes back 
beneath Poupart's ligament, one part goes to the skin of the thigh 
and the other part to the spermatic cord in the male, and to the 
vicinity of the vaginal orifice in the female. The external cutaneous 
nerve also passes back beneath Poupart's ligament and goes to the 
skin outside the hip and thigh. 

The obturator nerve, which is of large size, passes along the 
side of the pelvis, with the obturator vessels, and perforates the 
obturator membrane, being distributed to the external obturator 
muscle, the pectineus gracilis, and the adductor. The anterior 
crural nerve is the great nerve of the front of the thigh, and is the 
largest of those which quit the lumbar plexus. Coming out from 
the psoas it passes down and divides, giving off nerves to the skin of 
the front and inside of the thigh, to the skin of the inner side of the 
leg and foot, and also branches to the sartorius, pectineus, and 
quadriceps extensor muscles. The superior gluteal nerve passes 
out in front of the pyriformis, and is distributed to the glutei 
muscles. 

The great sciatic nerve, which is the largest nerve in the 
body, passes out through the sacro-sciatic notch behind the pyri- 
formis muscle, and proceeds between the great trochanter and the 
tuberosity of the ischium, beneath the gluteus maximus, and (with 
the sciatic artery) resting upon the obturator internus and quadratus 
femoris muscles. It descends beside the adductor magnus to the 
popliteal space, bifurcating into two branches, called respectively 
the internal and external popliteal nerves. The first of these (which 
is the larger) continues down behind the popliteus muscle, and then 
takes the name of posterior tibial nerve, descending near the pos- 
terior tibial artery to the inner malleolus, and dividing into the 
internal and external plantar nerves. The former of these accom- 
panies the internal plantar artery, and is distribuied to the three 
inner (or tibia!) toes, and to the inner side of the fourth. The 
external plantar nerve goes to the fifth toe and outer side of the 
fourth, after crossing obliquely beneath the sole with the external 
plantar artery. The posterior tibial nerve supplies all the flexor 
muscles of the foot and toes, and the skin of the sole of the foot 
and part of the back of the leg. The second division of the 
popliteal nerve, i.e., the external popliteal, or peroneal nerve, curves 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 283 

round the head of the fibula beneath the peroneus longus and 
divides into two branches. The first of these, called the musculo- 
cutaneous nerve, descends between the extensor longus digitorum and 
the peronei muscles to the dorsum of the foot, where it ramifies. It 
supplies the peronei and skin of the front of the leg and dorsum of 
the foot. The second division of the external popliteal nerve is 
called the anterior tibial. It passes obliquely inwards beneath the 
extensor longus digitorum, and descends with the anterior tibial 
vessels to the ankle, where it divides, one part continuing on to the 
first interosseous space, the other passing outwards obliquely beneath 
the extensor brevis. It supplies the tibialis anticus and the extensors 
both long and short, as well as the skin of part of the dorsum of 
the foot. 

Of the smaller branches from the sacral plexus, the pudic nerve 
is that which supplies the generative organs and adjacent parts. 
The other nerve, the origin of which has been mentioned, is the 
small sciatic nerve, which arises behind the pyriformis, descerds 
beneath the gluteus maximus, and gives branches to that muscle 
and to the skin of the lower part of the buttock and back of the 
thigh. 

§ 20. The nerves of the tail come from the sacral plexus, 
which gives origin to a lateral nerve which runs along each side of 
the tail, giving off branches to the muscles. The more anterior 
part of the tail is also supplied by branches of the cauda equina, 
which are continued into it. 

§ 21. The sympathetic system consists of an immense number 
of small nerves (of pale fibres), with many ganglia scattered through 
the body, and specially connected with the viscera and blood-vessels, 
the whole system being connected with the spinal system of nerves 
by two elongated, gangliaied cords, which extend from before 
backwards, one on each side of the ventral aspect of the skeletal 
axis, from the pre- sphenoid to the tail. It is with these two longi- 
tudinal cords that the several filaments already noticed as passing 
from the spinal nerves close to their roots, unite. The sympathetic 
visceral nerves, in passing to the organs which they supply, traverse 
those folds of membrane (the mesenteries) which, as we have seen, 
suspend the viscera from the backbone. 

In the trunk, the sympathetic nerves and ganglia are here and 
there congregated together, forming great plexuses, whence other 
nerves proceed. 

In the head, filaments of the sympathetic communicate with 
all the cranial nerves (except those nerves of special sense, the 
"optic" and "olfactory" nerves), and where these unions take 
place, certain ganglia are developed. 

The ootids, placed symmetrically one on each side of the ventral 
aspect of the vertebral column, from the base of the skull to the 
tail, each developes ganglia, which in the trunk correspond in 
number with the dorsal and lumbar vertebrae. These cords are 
connected in front with sympathetic nerves of the skull, while 



284 THE CAT. [chap. is. 

posteriori)* they meet together and terminate in a single elongated 
ganglion beneath the tail. 

The filaments which unite the several ganglia with the several 
spinal nerves are formed partly of white and partly of grey fibres, 
and the same is the case with the horizontal cords which connect 
together, on each side, the series of ganglia. The white fibres are 
deemed to come from the spinal system. 

In the neck, the sympathetic is intimately connected with the 
pneumogastric. 

The great plexuses of the sympathetic are three in number : one 
in the thorax, called the cardiac plexus ; one in the abdomen, called 
the solar plexus ; and one in the pelvis, called the hypogastric plexus. ' 
Each is a single, median structure, and each furnishes sympathetic 
nerves to adjacent viscera. 

The thoracic parts of the gangliated cords, lie on a line with 
the heads of the ribs, between the pleura and the intercostal vessels. 
Occasionally two of the ganglia of each side may coalesce. 

The branches given off by the first five or six ganglia go mostly 
to the aorta and adjacent parts, and are small in size ; but those of 
the more posterior ganglia join together to form on each side the 
splanchnic nerve, which penetrates the diaphragm and goes to a 
special ganglion, called " semilunar," which is situate in the solar 
plexus. 

The lumbar parts of the gangliated cords approach each other, 
lying on the ventral aspect of the bodies of the vertebrae, along the 
inner margin of each psoas muscle. In the sacral region the cords 
are much smaller, and they approach each other yet more, uniting 
together in a single median ganglion [ganglion impar) beneath the tail. 

Of those complex entanglements of nerves and ganglia, the great 
plexuses, the first, or cardiac plexus, lies on the base of the heart 
and on the aorta and pulmonary artery. It receives the cardiac 
branches of the pneumogastric nerves, with the cardiac branches from 
the cervical ganglia of the sympathetic. It constitutes the nervous 
system of the heart. 

The solar (or epigastric) plexus is the largest of all, and lies in 
the anterior part of the abdomen, between the stomach, aorta, and 
piliars of the diaphragm, and between the suprarenal capsules. It 
receives not only the splanchnic nerves, but also some branches from 
the pneumogastric. It contains several ganglia, the two largest of 
which are called semilunar. It gives off very many branches, ac- 
companying the arteries to the different abdominal viscera. 

The hypogastric plexus is that which furnishes sympathetic 
branches to the pelvis, and lies between the right and left iliac arteries. 
It receives branches from the lumbar part of the gangliated cords, 
and from the plexuses in front. Unlike the solar plexus, this one 
contains no ganglia. It sends backwards two prolongations, one on 
each side of the pelvic viscera, these prolongations forming what is 
specially called the pelvic plexus, nerves of which are spread about 
the pelvic viscera, especially the bladder and generative organs. 



chap, ix.] XERVOVS SYSTEM AND OBGANS OF SEXSE. 285 

The sympathetic system may be regarded either as a separate 
svstem or as but a series of internally directed branches of the 
spinal nerves of each side of the body. According to this Litter 
view, each spinal nerve divides into three branches. One of these 
branches passes upwards as a dorsal nerve ; another follows the 
bodv wall — the ventral branch of each spinal nerve — while the third 
branch (hitherto called the filament to the sympathetic) passes in- 
wards in the line of the mesenteries. These last inner branches or 
filaments are serially connected by horizontal nerves, i.e., by the two 
longitudinal gangiiated cords. 

The sympathetic filaments which ramify around the arteries are 
termed the uaso-motor nerves. 



THE ORGANS OF SPECIAL SEXSE 

§ 22. Feelings of different kinds will be more fully considered 
amongst the functions of the nervous system, but their existence 
must be recognized in treating of the organs which minister to them, 
and these have now to be considered. 

The special organ of touch is the skin, above all the skin of 
the muzzle, tongue and digits. The nerves of the vibrissa? and the 
touch corpuscles are the agents which induce this sensation. 

The structure of the skin, with its papilla?, the touch corpuscles and 
Pacinian bodies have been already described in the second chapter. 

The nerves at their ultimate terminations in the skin, divide, and 
may form small terminal plexuses, or enter touch corpuscles or 
Pacinian bodies (as earlier described), or terminate in end lulls, 
which are spheroidal bodies about ¥ -g- of an inch in diameter. 
Each of these consists of a capsule of connective tissue, with nuclei 
— the capsule containing a core of clear, soft, granular matter. 

§ 23. The organ of taste is, in the main, the tongue, especially 
its back part, but the under surface of the soft palate also seems to 
participate in the faculty. The tongue with its three kinds of 
papilla?, has been already described. It is supplied with three 
nerves : (1) the gustatory, (2) the lingual branch of the glosso- 
pharyngeal, and (3) the hypoglossal. The last is motor, but the first 
two are sensory. The gustatory nerve goes to the mucous membrane 
and papilla? of the fore-part and sides of the tongue, the lingual 
branch of the glosso-pharyngeal goes to the mucous membrane at 
the base and side of the tongue, and especially to the circumvallate 
papilla?. 

The soft palate and also the anterior pillars of the fauces, have 
short, soft papilla? on their mucous membrane, and these parts are 
supplied with fibres from the superior maxillary and glosso-pharyn- 
geal nerves. 

The parts, however, which by their contact with foreign bodies 
are the actual ultimate occasions of the sense of taste are certain 
minute structures called gustatory cells, which are enclosed in 
other structures called gustatory bulbs. These latter are very small 



286 THE CAT. [chap. ix. 

spheroidal capsules situated beneath the epithelial surface, and 
opening' upon that surface by a minute aperture termed the gustatory 
pore. These bulbs lie in sheltered situations, such as e.g., in furrows 
on the tongue and in the outer (lateral) surfaces, of the circumval- 
late papillae — the pores opening into the fossa surrounding each such, 
papilla. There are some hundreds of such circumvallate gustatory 
bulbs, while comparatively few are found upon the fungiform 
papillae. Each bulb encloses a number of horny, spindle-shaped 
bodies, with their apices directed towards its pore. These are called 
investing cells, and are of epithelial nature ; they serve to enclose 
and protect the actual gustatory cells, each of which is a spheroidal 
mass of protein substance, ending above (distally) in a rod-like 
filament. These filaments about reach to the aperture of the 
gustatory pore. At their base or proximal end each gustatory cell 
gives off a minute filament, which becomes continuous with one of 
the ultimate ramifications of the nerves of taste. 

Thus the ultimate organs of taste appear to be so many minute 
rods proceeding from cells. 

§ 24. The organs of smell are contained within the cavity of 
the nostrils, protected by bones and cartilages. The bones have 
already been described, and extend backwards from the anterior to 
the posterior nares. 

The passage which connects these openings gives entrance to 
currents of air, which habitually pass in through them in respira- 
tion, and exclusively through them when the mouth is closed. 

But these currents only pass through the lower part of the nasal 
cavity, which on that account is called the respiratory portion of it. 
The nasal cavity, however, ascends much above this, namely, up 
between the orbits, and it is there that the sense of smell is exercised, 
and into this part the odour-bearing air can only pass by the slow 
process of diffusion, unless by the action of sniffing, which, draws 
it upwards into that upper part of the nasal cavity. 

The cartilages of the nose are dependencies of the median 
cartilage or cartilage of the septum, which continues on the more 
posteriorly situated vertical bony septum (formed by the median 
ethmoid and vomer), reaching up to the nasal bones and in front of 
them. Below, it rests (in front of the vomer) on the median raised 
ridge, formed by the junction of the two maxilla3, on the upper 
surface of the maxillary part of the bony palate. Above, it expands 
so as to serve as a continuation of the nasal bones, while lateral 
prolongations of the median cartilage extend out, one on each side, 
and are so curved (first outwards, then downwards, and then inwards) 
that each nearly surrounds (while it keeps open) the lower part of 
one of the nostrils. Behind, each is attached to the maxilla. On the 
dorsum of the distal end of the median cartilage (between its 
lateral expansions) there is a deep median groove. 

The nasal fossa? are those cavities the bony walls of which have 
been already described. They extend from the upper surface of the 
palate below, to the under surface of the cribriform palate above, 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 287 

and are therefore higher in their middle part than either at the 
anterior or posterior end — at the anterior and posterior nares. These 
fossae communicate with the frontal sinuses, as has already been 
noted in describing the skull. The outer wall of each nasal fossa 
exhibits the three prominences formed by the superior and inferior 
mass of cells of the lateral ethmoid, between which is the upper 
meatus as well as that formed by the maxillo-turbinal, above which 
is the middle meatus, while the inferior meatus is below the maxillo- 
turbinal. These parts are all invested with thick mucous membrane, 
so that their projection inwards and antero-posteriorly is much more 
marked in the living or freshly -killed animal than it is in the dry 
skeleton. 

At the roof of the fossa are the openings into the sphenoidal 
sinuses into which the mucous membrane is prolonged. 

In the inferior meatus is the lower termination of the lachrymal 
canaL 

The mucous membrane which invests the nasal fossae is called 
the Sckneiderian (or pituitary) membrane. It is very vascular, and 
is inseparably united with the periosteum and perichondrium of the 
different parts. At the margins of the anterior nostrils it becomes 
continuous with the external skin, while at the posterior nostrils it 
becomes continuous with the mucous lining of the pharynx. 

The epithelium, which coats the mucous membrane varies in 
character in different places. That portion which lines the lower part 
and front of the nose is lined with squamous epithelium. In the 
respiratory part of the cavity (i.e., the maxillo-turbinal bones and 
all the parts below them) it is columnar and ciliated. In the olfac- 
tory part of the cavity (i.e., the two masses of the lateral ethmoid 
and the upper part of the septum) the epithelium is columnar but 
not ciliated. The mucous membrane of this special, olfactory part 
is very thick, soft and pulpy. 

The special organs of smell are certain peculiar bodies called 
olfactory cells, spindle-shaped, nucleated, and placed between 
the columnar epithelial cells. Each such spindle-shaped cell sends 
out towards the surface a rod-like process, provided with long, 
slender hairlets which project slightly beyond the surface. At its 
opposite pole the cell sends out a deep process, which appears to be 
continuous with the ultimate ramifications of the olfactory nerves. 

Thus the ultimate organs of smell appear to be so many minute 
rods proceeding from cells. 

The olfactory nerves come off from the under surface of the 
flattened end of each olfactory bulb, and piercing the cribriform 
plate are distributed to the mucous membrane which invests the two 
lateral masses of the ethmoid and the upper part of the median 
septum. The nerves ramify in a plexiform manner over these parts, 
forming a fine net- work. They are entirely composed of pale fibres, 
and are finely granular. 

The rest of the mucous membrane is provided with nerves which 
are ramifications of the fifth pair of cranial nerves. 



288 THE OAT. [chap. ix. 

Thus the maxillo-turbinals do not minister to smell, but serve, as 
it were, to strain and also to warm the air at first received within 
the nostrils, and which is subsequently diffused into the truly 
olfactory upper chamber. 

In connection with the nasal cavity a peculiar structure, called 
the organ of Jacobson, may be noticed. This is a small tubular sac 
which is placed on each side of the median septum upon the nasal 
surface of the palatine plates of the premaxilla and maxilla. Pos- 
teriorly it ends blindly, but anteriorly it opens by the incisive 
foramen into the cavity of the mouth, the mucous membrane of 
which is continued into it. It receives nerves from the olfactory 
bulb, which enter into its hinder end and which terminate in struc- 
tures analogous to the filamentary terminations of the olfactory 
nerves of the sensory part of the nasal cavity. Though these organs 
open into the mouth, and not into the nasal fossa?, yet they have an 
essential relation to the latter, as will appear in the next chapter. 

§ 25. The organ of sight, the eye, consists, as has been already 
said, of a globe of more or less soft tissues, into the outer surface of 
which muscles are inserted — the whole being protected and enclosed, 
except in front, by dense fascia and muscle, or else by the osseous 
plates which form the imperfectly closed bony socket or orbit of the 
eye. Into this ball, moreover, as has already been stated, the optic 
nerve enters, passing through the optic foramen to its posterior part. 

In front, where the bony protection ceases, the ball is protected 
by an extension of skin above and below, forming the eyelids or 
palpebral. These have their outer surfaces covered by the external 
skin, while each is lined internally with mucous membrane, and the 
mucous membranes of both the upper and lower eyelid of each eye 
are continued one into the other by that transparent membrane 
which covers the front of the eyeball, and is called the conjunctiva. 
Internally they are strengthened by a strong fibrous membrane. 

The upper eyelid is raised by the special muscle called the 
" levator palpebrae," which is supplied by a branch of the oculo- 
motor nerve. A circular sphincter muscle (the orbicularis palpe- 
brarum) extends through both eyelids, and, by its contraction, closes 
them. There is no special depressor of the lower eyelid. The 
point on each side where the eyelids unite is termed the angle, or 
canthus, of the eye. At its inner canthus are two minute apertures 
(to receive the lachrymal secretion) called puncta lackrymalia. 
There is also a large fold of membrane, or third eyelid — the plica 
semilunaris or membrana nictitans — which rises from the bottom and 
inner angle of the orbit and rests upon the eyeball. It has a 
cartilage at its margin which strengthens it (Fig. 130, MN). 

Immediately beneath the thin delicate outer skin of the eyelids, 
and adherent to it, are the fibres of the orbicularis muscle, and 
beneath these are the fibrous membranes of each eyelid (defining 
its shape and giving it firmness), and then the levator palpebraa 
muscle. On the inner surface of each lid are certain sebaceous 
follicles, or tubes, termed Meibomian glands, which extend vertically 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 289 

on the inner surface of each palpebral fibrous membrane. Each 
tube is lined by mucous membrane, and forms an oily secretion. 

The conjunctiva is vascular, red, opaque, and somewhat thick 
where it lines the eyelids, but where it is reflected from them (over 
the ball of the eye) it is transparent, almost colourless, and has but 
very few blood-vessels. Over the coloured part of the eye and the 
pupil, the conjunctiva is quite transparent, and without vessels, and 
consists almost entirely of epithelium. 

The lachrymal gland, which secretes the tears, lies at the 
upper and outer part of the orbit. It is a very small racemose 
gland, with ducts which open on the inner surface of the upper eye- 
lid, just above the outer can thus. Tears, are a clear, saline, 
alkaline fluid, with a minute portion of albuminoid matter. About 
1 per cent, is the quantity of solid matter which they contain. 
Having traversed the surface of the conjunctiva, the tears enter 
the puncta lachrymalia (before noticed), which are the orifices of 
two short membranous canals (the lachrymal canals) which pass 
inwards (towards the nose), and open into a membranous tube, the 
■nasal duct, which descends, through the bony lachrymal canal before 
described, to empty itself into the anterior part of the inferior meatus 
of the nose. This canal, formed of fibrous and elastic tissue, adheres 
closely to the bones it adjoins in its passage. It is lined with mucous 
membrane, which is thus continuous with the conjunctiva above and 
with that of the nasal fossa below- The epithelium which coats its 
mucous membrane is ciliated. 

The Harder ian gland is a small organ situated at the inner 
canthus of the orbit. It is oval and somewhat like a small bunch 
of grapes. It secretes a thick, whitish fluid, which escapes from 
one or two orifices which open beneath the membrana nictitans. 

The eyeball is embedded in fat, from which it is separated by a 
layer of fascia. It is spheroidal and composed of three investing 
membranes, one within the other, enclosing certain fluid and solid 
contents. 

The first membrane is the sclerotic and cornea, the second is the 
choroid and iris, and the third is the retina. 

The fluid contents is made up of the aqueous and vitreous humours. 

The solid contents is the lens, with the capsule enclosing it. The 
shape of the eye-ball is really that of a large segment of one sphere, 
with a small segment of a lesser sphere affixed to it in front. The 
proportion between these spheres is as eleven to seven. 

The first or outer membrane is partly opaque — the sclerotic 
— while that part of it which is called the cornea is transparent. 

The sclerotic invests the larger part of the eyeball. It is formed 
of very dense fibrous tissue, with elastic tissue and with stellate and 
fusiform nucleated cells. By its solidity and toughness the sclerotic 
maintains the globe of the eye in its proper shape. It is white 
externally and smooth, except as regards the insertion of the orbital 
muscles into it. It is thickest at the back and thinnest near the 
margin of the cornea. The optic nerve pierces the sclerotic slightly 

u 



290 THE CAT. [chap, ix 

on the inner side of the antero-posterior axis of the eyeball. The 
membranous sheath of the whole nerve becomes continuous with the 
sclerotic, as do also the investments of the different bundles of nerve 
fibres of which the whole optic nerve is composed. On this account 
the part of the sclerotic where the fibres enter is called the lamina 
cribrosa. There are a few blood-vessels in the sclerotic, especially 
near the margin of the cornea. 

The cornea (or the transparent and anterior part of the fibrous 
coat of which the sclerotic forms the larger portion) covers the 




Cm 

Fig. 134.— Diagram representing a Vertical Section of the Cat's "Eye, 



Scl. Sclerotic coat. 

Cn. Cornea. 

R. The attachment of the tendons of the recti 

muscles. 
Ch. The choroid. 
Cv. The ciliary processes. 
Cm. The ciliary muscle. 



Jr. The iris. 

Aq. The aqueous humour 

Cr. The crystalline lens. 

Vt. The vitreous humour. 

Rt. The retina. 

Op. The optic nerve. 



anterior part of the eyeball, and has its surface rather more curved 
than is that of the sclerotic. It is also composed of fibres which are 
softer and much more indistinct than those of the sclerotic, with 
which they are nevertheless continuous, some fibres being opaque at 
one part of their course and transparent at the other part. Between 
the layers of fibres there are fusiform nucleated cells. The cornea 
yields chondrin on boiling, unlike the sclerotic, which yields gelatine. 
Each surface of the cornea is invested by a most delicate, structure- 
less transparent membrane or elastic lamina. 

The second or median membrane also consists of two parts : the 
choroid and iris. The choroid is a membrane placed within the 
sclerotic, covering the sides and back of the wall of the eyeball, 
except where the optic nerve pierces it. It extends forwards nearly 
to the margin of the cornea, where it ends in a number of irregular 
folds, called ciliary processes. These project inwards towards the 
centre of the eyeball. 

The choroid is tough externally where it is connected with the 
sclerotic by loose connective tissue ; internally, it is smooth and dark 
coloured, being lined by a layer of dark pigment cells everywhere 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 



291 



except at the ends of the ciliary processes, and at a certain consider- 
able part which is called the tapetum, and is of a golden yellow 
colour.* Tliis tapetum is a roundish patch, occupying most of the 
back of the inside of the choroid, and including within it the en- 
trance of the optic nerve, which enters towards the lower margin of 
the tapetum. It is this tapetum which gives the eyes of cats that 
luminous appearance in obscurity, by reflecting the light — a pro- 
perty which is supposed to assist their nocturnal vision. The choroid 
is an excessively vascular fibrous membrane, the vessels becoming 
more minute as they advance forwards, and forming a fine capillary 
network ending very near the margin of the cornea, in what is called 
the ciliary ligament. This ligament is a circular band of connective 
tissue and organic muscular fibre, which unites the choroid with the 
sclerotic external to it. 

The arteries of the choroid come from the ophthalmic artery. 
"Within the outer vascular layer of the choroid a layer of capillary 
vessels is distinguished by the name of tunica Ruyschiana, or chorio 
papillaris. Within this, again, a structureless (or slightly fibrous) 
membrane named the vitreous layer is described, while inmost of all 
is the pigmentary layer, of closely placed polygonal pigment cells. 

The iris is that coloured part of the eye which is apparent around 
the pupil, and which may be differently coloured on its front surface, 
in different cats,f but is covered with dark pigment on its hinder or 
deep surface. It consists of fibrous tissue and organic muscular 
fibres. 

At its outer border the iris is continuous with the choroid and 
ciliary ligament, and is connected with the cornea, while its free 
inner border forms the outer margin of the pupil of the eye — it being 
a sort of curtain with a hole in it, about half an inch across, sus- 
pended in the more anterior part of the interior of the eyeball, and 
resting on the anterior surface of the lens. 

The iris is very, and very suddenly, contractile (in spite of the 
organic nature of its muscular fibres), and has two muscles. The 
first, or sphincter, is a flat band close to its free inner margin, and 
on its posterior surface. The dilating muscle, on the other hand, 
is formed of fibres which pass inwards on all sides towards the 
margin of the pupil from the circumference of the iris. In ob- 
scurity the pupil is widely open, with a circular opening through 
contraction of the radiarting fibres of the iris. In bright light the 



* At my request Mr. Henry Power has 
been so kind as to examine the cat's eye 
with the ophthalmoscope. As to the result 
of his examination, after noting the non- 
appearance of that spot known in man 
as the fovea centralis or yellow spot, he 
expresses himself as follows:— "I owe 
you thanks for directing my attention to 
one of the most beautiful things I have 
ever seen. Imagine a dense, yet lumi- 
nous velvety-blackness below, bounded 
by a nearly horizontal line, just above 



which is a pearly spot ; the entrance ot 
the optic nerve. This presents the usual 
vessels emerging from it. The disc is 
surrounded by a sapphire l*lue zone of 
intense brilliancy, passing into metallic 
green ; and beyond this the tapetum 
shines out with glorious colours of pink 
and gold, with a shimmer of blue and of 
green. It is really lovely." 

f Or even in the two eyes of the same 
cat. 

u 2 



292 



THE CAT. 



[CHAP. IX. 



opening contracts m-ore and more till it is reduced to an extremely 
narrow vertical chink. This is probably due (as has been sug- 
gested to me by my friend Mr. Henry Power) to the greater con- 
traction of the superior and inferior radiating fibres than of those 

which radiate outwards and inwards. A 
muscle called the ciliary muscle consists 
of a ring of radiating organic fibres which 
take origin in front from the inner surface 
of the sclerotic, close to the cornea, and 
pass outwards and backwards to the cho- 
roid membrane, opposite to the ciliary pro- 
cesses. By their contraction these fibres 
pull forward the choroid, and so render the 
ciliary ligament less tense. The muscle 
thus tends to draw the choroid and retina 
together like a bag round the vitreous 
body, pressing the lens forwards, which 
is supposed to be thus indirectly made 
less flat. There are a few more inwardly 
situated fibres which run circularly (nearly 
at right angles to the rest), and fcrm 
part of the ciliary ligament as before men- 
tioned. 

Inmost of all the coats of the eyeball 
lies a soft delicate membrane of nervous 
matter with connective tissue — the retina. 
It extends forwards almost to the ciliary 
processes, and ends anteriorly in a finely 
toothed margin called the ova serrata, and 
thence to the tips of those processes the 
retina is continued on by a transparent 
layer, the pars ciliaris retina, consisting 
of nucleated cells which are not nervous, 
but part of the membrana limitans interna. 
Slightly on the inner side of the middle of 
the retina, at the back of the eye, is an 
oval prominent spot, the porus opticus, 
where the optic nerve enters, and whence 
the vessels of the retina radiate. This 
is a blind spot. 

The retina is an extremely complex membrane, consisting of about 
seven layers of different forms of nervous tissue, supported and con- 
nected by a most delicate framework of connective tissue. 

The outermost layer, that which comes next to the pigment layer 
just described, is what has been called the membrane of Jacobson. 
It consists of a multitude of minute and delicate nervous rods, 
placed with their ends directed outwards and inwards. Amongst the 
rods are scattered at regular intervals a less number of nervous cones, 
placed with their apices outwards. 




Fig. 135.— Diagram represent- 
ing a Section of the Re- 
tina. 

ch. s. Outer, or choroidal surface. 

in. s. Inner surface, or that next 
the vitreous humour. 

a. Layer of nerve-fibres at inner 
surface of retina. 

6. Ganglionic layer of large nerve- 
cells. 

c. Inner molecu'ar layer. 

d. Inner nuclear layer. 

e. Outer molecular (inter-nuclear) 

layer. 
/. Outer nuclear layer. 
g. Layer of rods and cones. 
h. Layer of pigment cells— next 

the choroid. 
Ml. Membrana limitans. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 



293 




The rods stand in close apposition. The cones * are not so close 
set and do not extend as far outwards as do the rods. Both structures 
become shorter as they approach the ora serrata. 

Within the rods and cones is a thin layer of granulated substance, 
connected with the fibres in which the rods and cones end in- 
ternally. This layer is the external granular, or outer nuclear layer, 
within which is the internal granular, or inner nuclear layer, formed 
of nucleated cells and fibres, separated from the former by the inter- 
granular, or internuclear layer, formed of plexiform tissue enclosing 
a few nuclei and smooth cells, with 
coarser fibres running parallel to the 
surface of the retina. 

Within the internal granular layer, 
again, is a thicker inner molecular 
layer (or internal granulated layer), 
which contains much connective 
tissue, within which again is a layer 
of ganglionic cells, and lastly and 
most internally, is a layer of fibres of 
the optic nerve, ramifying on the 
inner surface of the retina, and con- 
nected with the ganglia placed ex- 
ternal to it. This layer of nervous 
fibres is bounded within by an ex- 
tremely delicate, glossy membrane, 
the membrana limitans, which is 

continued forwards as the pars ciliaris retina?, and becomes con- 
tinuous with the suspensory ligament of the lens. Doubtless the 
rods and cones are continuously though complexly connected with 
the ganglia and fibres of the innermost layer. 

At the point of entrance of the optic nerve {i.e., at the blind spot) 
rods and cones are wanting. In the eye, as in the nose and tongue, 
the special sense is subserved by minute nervous rods proceeding 
from cells. 

Filling up the great concavity bounded by the membrana limitans 
lining the innermost layer of the retina is the vitreous humour 
(or vitreous body), forming nearly four-fifths of the ball of the eye. 
This is a transparent, jelly-like, almost quite fluid mass enclosed (as 
just observed) in the membrana limitans of the retina. 

The vitreous humour is reducible to water with a few salts and a 
little albumen. It appears to consist of concentric layers of slightly 
different density, but not separated from one another by any 
membrane. 

The crystalline lens of the eye is a transparent, doubly convex 
solid structure, interposed between the posterior surface of the 



Fig. 136.— Laminated Structure of the 
Crystalline Lens, shown after 
hardening in alcohol. 

1. Central portion. 

2, 2, 2. Concentric lamina, which have 

become detached along the radiating 
lines of the external surface of the 
lens. 



* The cones must be looked upon as 
collections of nerve terminations ; they 
appear to be longitudinally striated, and 
they pass into a thick fibre (cone-fibre), 



which consists of a bundle of the finest 
axis cylinders, which separate in the 
granular layers of the retina. 



294 THE CAT. [chap. ix. 

iris and the anterior surface of the vitreous humour. It is somewhat 
harder within than superficially. It consists of albuminous substance, 
and is non- vascular. It is really made up of a multitude of fibres 
(each a flattened hexagonal prism, about T oVo °f an i ncn wide), with 
serrated edges and a nucleus. These are so connected that the lens 
is practically made up of concentric layers of fibres, as becomes 
evident after immersion in alcohol. The lens is not quite spherical, 
but is compressed from within outwards, that dimension being less 
than its transverse diameter. 

The capsule of the lens is a transparent, glassy membrane, which, 
is very elastic, and closely invests the lens itself. Its anterior surface 
is in contact with the iris, its posterior surface adjoins the vitreous 
humour. From the extreme circumference of the lens it sends off a 
membrane, the suspensory ligament of the lens, which becomes con- 
tinuous with the choroid and with the membrana limitans of the 
retina, where it has become the pars ciliaris retina?, behind the ciliary 
processes. It thus divides the chamber in front of the lens from 
that of the vitreous humour. Just behind that part of it which 
adjoins the lens, it is slightly separable from the front of the vitreous 
humour, and when separated leaves a space which has been called 
the canal of Petit, but this is no true persistent canal, but only a 
yielding interspace affording room for change of place in the lens, 
and consequent focal adjustment. 

The aqueous humour is the fluid which fills the front chamber 
of the eye between the iris and lens, and the cornea. It scarcely 
differs in composition from water, but contains some solids in 
solution — chiefly chloride of sodium. A small portion passes 
"behind the iris, in what is called the posterior chamber of the 
aqueous humour. 

The direction of the eyes is determined, apart from the position of 
the body, neck, and head, by the action of the orbital muscles, 
of which the recti severally pull the cornea in four directions, while 
the obliqui roll the eyeball on its axis, and pull it a little forwards 
and inwards. The choanoid muscle tends to pull it backwards. 
The eyelids protect the ball of the eye from foreign substances and 
from excessive light, and hinder the too rapid evaporation on its 
surface, the moisture of which is secured by the lachrymal secretion, 
the superfluous quantity of which escapes to the nose (through the 
juncta lachrymalia and nasal duct), while the secretion of the 
Meibomian glands tends to check its overflow beyond the margins 
of the eyelids. 

The structure of the eye, as an optical instrument, is that of 
a camera obscura filled with water, with a circular aperture, behind 
which is a partition, or diaphragm, with another and smaller circular 
aperture immediately in front of a bi-convex lens. 

The lens, according to the laws of optics, concentrates the rays 
coming from every point in front of it to other points behind it, and 
thus throws upon any surface situated at due focal distance, an 
inverted image of the objects in front of it. The surface behind, 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 



295 



upon which the image is thrown, is the retina, and the perfection of 
the image is increased by the iris, which acts like any other 
diaphragm by moderating the light and cutting off marginal rays, 
the effect of which, if admitted, would be to produce the imperfection 
called spherical aberration. The organic fibres of the iris spon- 
taneously act to exclude or admit light through the pupil, which 
dilates in obscurity and contracts in bright light, in the manner 
already described. 

The different densities of the different media through which the 
light has to pass in traversing the eye corrects another kind of 
imperfection due to the scattering of colour, and renders it an 
achromatic instrument. 

Not only is the image in the eye inverted, but each eye sees any 
object from a slightly different point of view. It is this grasp, as it 
were, of an object on both sides by the two eyes, which gives rise to 
the apprehension of solidity * and relief. 

For distinct vision, the rays of light must be brought to a focus 
on the retina. Now, without moving the body, neck, or head, the 
eyes can be so directed alternately to nearer or to more distant 
objects as to produce distinct perception of each successively. Such 
movement is the focussing of rays coming from points varying in 
remoteness. The way in which this adjustment is brought about is 
supposed to be by the action of the ciliary muscle, and the physical 
properties of the lens. The latter is highly elastic, and tends to be 
more convex in front than is ordinarily the case. The ciliary 
muscle, pulling the choroid, relaxes the ciliary ligament, and 
therefore the pressure of the capsule on its contained lens, which 
immediately becomes more convex, and so becomes accommodated 
to the perception of nearer objects. f 

§ 26. The organ of hearing is divisible into three parts : the 
external, the middle, and the internal ear. 

The external ear consists of a cartilaginous, membranous, and 
muscular structure, projecting conspicuously upwards from the side 
of the head, and called the pinna or auricle, together with the 
passage leading inwards from the deeply situated lowest portion of 
the pinna, which passage is the external meatus, or tube leading to 
the internal ear. 

The pinna has the form of the wall of a cone, cut obliquely down- 
wards and outwards from its apex, the section being curved a little 
upwards at the last, so as to make the lowest part of this conic section 
almost semicircular. The pinna stands up above and behind the 



* It is the special artificial imitation 
of two such views placed side by side at 
a suitable distance, which produces the 
illusion of the stereoscope, the relation of 
each view to its proper eye being main- 
tained. If the views be transposed, so 
that the view which would naturally 
present itself to the right eye be pre- 
sented to the left, and vice versa, as by a 



pseudoscope, then the opposite appearance 
of a hollow or excavated surface is pro- 
duced. 

+ The above is the commonly received 
doctrine on the subject ; but fishes have 
a ciliary muscle, although the lens in 
them is globular. It may be, therefore, 
that its action is not yet correctly under- 
stood. 



296 THE CAT. [chap. ix. 

opening of the ear passage. It is deeply concave on the surface, 
which is turned outwards and forwards, and convex on its inwardly 
and backwardly-turned surface. It is hairy within and without, but 
the hairs within are not numerous, though very long. Externally, 
the pinna is covered with short hairs. Its inner surface presents 
a variety of prominences and fossa), which aid in collecting and 
concentrating the sonorous waves which impinge upon the organ. 

Immediately in front and externally, at the bottom of the external 
opening, is a small rounded prominence, the tragus, and im- 
mediately opposite it is a double prominence with an intervening 
concavity, the anti-tragus, into the concavity of which the tragus 
exactly fits. From the anti-tragus a low ridge runs upwards and 
backwards to the margin of the pinna. A little further in, another 
similar ridge runs (nearly parallel to that just mentioned) from the 
margin of the pinna downwards to a very small prominence behind 
the anti-tragus. Within and behind the tragus there is another 
vertical undulating ridge, the (post-t rag us, while between its summit 
and the tragus is a deep, rounded depression. 

Behind and above the summit of the post-tragus is the deepest 
concavity of the concha, from the midst of which a singularly pro- 
minent process, with a pedunculated appearance, projects inwards, 
which process may be called the supra -tragus. A slight, short 
ridge runs downwards and backwards from the lower margin of 
the fossa in which the supra-tragus is placed. The cartilage of 
the pinna is large and complexly-shaped, with a reduplication in 
front. There is a reduplication of skin at the lower part of the 
posterior margin of the pinna, producing a sort of pouch. 

The pinna is attached to two cylindrical cartilages, which follow 
each other like two successive segments of a telescope, and form the 
cartilaginous part of the meatus auditorius externus. 

A distinct body, called the scutiform cartilage, is only connected 
with the pinna by ligaments, yet has muscles inserted into it which 
indirectly move the ear. It lies on the temporal fossa just behind 
the orbit, w 7 ith its long axis antero-posterior, and enclosed in pre- 
auricular aponeurosis. It can glide to and fro in the temporal 
aponeurosis. 

The external auditory meatus extends straight in from the 
pinna to the drum of the ear, or tympanic membrane. Its outer 
part is formed by cartilage, the rest by bone, as has been before 
described.* At its inner end the bony tube is grooved at its sides 
and floor, and into this groove the tympanic membrane is fixed. 

The meatus is lined with mucous membrane, which is reflected 
over the outer surface of the tympanum so as to form a coecal 
mucous tube. In the bony part of the meatus this membrane is 
thin, and closely adherent to the periosteum, but in its cartilaginous 
part it is thicker, and bears hairs, together with sebaceous and 
oleaginous glands. 

* See ante, p. 64. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 



297 



The middle part of the ear, or tympanum, has been already 
described in part in the description of the temporal hone.* It is a 
chamber entirely enclosed in the temporal bone, but has certain 
apertures in its walls. It is separated off from the external meatus 
by the tympanic men.brane, but it communicates with the pharynx 
through the Eustachian tube. 

The roof of the tympanum is formed by that portion of the 



Inc. 



P.Sc 



J£al 




Fig. 7 - Section of the Middle and Internal Ear of the Cat, much enlarged, showing 
the Membranous Labyrinth and its relations (and those of the Bony Labyrinth) 
to the Septum ok the Bulla, the Eustachian Tube, and the Tympanic Mem- 
brane. (From a drawing by Mr. Alban Doran.) 



The auditory ossicles are represented in outline 
as if transparent. The septum of the bulla 
is partly represented, but is cut away at * to 
show its relation to the labyrinth. The mem- 
branous labyrinth is represented by darker 
shading. 

Amp. Ampulla. 

C. Cochlea. 

E. c. Opening of Eustachian tube. 

E. sc. External horizontal semi-circular canal. 

Fr. Fenestra rotunda. (It lies almost entirely 
above the septum of the bulla and looks 
into the inner chamber; but its anterior 
margin bulges into the outer chamber.) 



Fo. Fenestra ovalis. 

Inc. Incus. 

Mai. Malleus. 

Mn. Manubrium. 

ML ML Outline of membrana tympani, with 

manubrium of malleus touching it. 
P. Sc. Posterior semi-circular canal. 
Sb. Septum of bulla. 
S. Sc Superior semi-circular canal. 
S. Stapes. 

St. Scala tympani of cochlea. 
Sv. Scala vestibuli of cochlea. 
*. Cut edge of septum of bulla. 



petrous bone which immediately adjoins the squamosal. Its outer 
trail has a very large opening closed by the tympanic membrane, 
and in front of its margin is the inner opening of the fissura Glaseri, 
before mentioned as transmitting the chorda tympani nerve. 

The tympanic membrane, which is nearly circular, lies obliquely, 
its outer surface looking somewhat downwards. It is very thin, and 
consists of fibrous and elastic tissue, the fibres radiating from about 
its centre, but there are also circular fibres, especially towards 
its circumference. 

The inner wall of the tympanum presents several openings and 
prominences. Towards its upper hinder part is a kidney-shaped or 
oval foramen called the fenestra ovalis. Somewhat in front of the 



* See ante, p. 63. 



298 TEE CAT. [chap. ix. 

fenestra ovalis is a rounded prominence marked by grooves for nerves 
and called the promontory. 

Another opening, called the fenestra rotunda, lies below and 
behind the promontory, and is, naturally, closed by membrane. 

Above the fenestra ovalis is a small depression or fossa, in which 
the stapedius muscle has its organ. 

The anterior part of the tympanum gradually narrows and 
becomes the proximal part of the Eustachian tube, which, as before 
said, is the canal which places the cavity of the middle part of the 
ear, in communication with the mouth. 

The Eustachian tube proceeds forwards and inwards and 
slightly downwards from the tympanum to the pharynx. Its 
anterior or distal part consists of cartilage and fibrous membrane. 

The tympanum is crossed by four small bones which proceed 
inwards from the inner surface of the tympanic membrane to the 
fenestra ovalis. These are the auditory ossicles. 

The outermost of these is called, from its shape, the malleus 
(Fig. 138, b), and consists of a quadrangular thickened portion, the 
head, with a rounded articular surface (as). Adjacent to this is a 
part called the neck (w), beneath which it expands, on one side, into 
a lamina of bone (/). From this extends a long, delicate, pointed 
process (pg), called the processus gracilis. From the inner side of 
the neck a large process (pm) projects, for the tendon of the 
tensor tympani muscle. Opposite this is a slight prominence, the 
processus brevis (pb), and from between these two last mentioned 
processes there extends a long curved production, the manubrium 
(emn), which is fixed on the middle of the tympanic membrane. 

The second bone is called the incus *or anvil (Fig. 138, c), also 
consists of a thickened part, with two processes. The thickened 
part, or body, has a concavo-convex articular surface, which unites 
with a corresponding surface on the body of the malleus, both sur- 
faces being provided with cartilage united by a synovial membrane. 

One process, the crus breve, projects backwards, and is attached 
by ligament to the hinder wall of the tympanum. The other 
process, the crus longum, which is longer, passes downwards behind 
the manubrium, while its end is bent suddenly inwards and articu- 
lates with a third bone, which is a minute rounded ossicle called the 
os orbicular e, and which is generally anchylosed to the end of the 
crus longum as the so-called processus lenticularis. The crus longum 
articulates by the intervention of the os orbiculare with the fourth 
auditory ossicle or stapes (Fig. 138, d), so called from its resemblance 
to a stirrup. That portion of it which resembles the part of a 
stirrup on which the foot rests is called its base, and the opposite end 
its head, while these are connected by the two crura which diverge 
from the neck. The base is fixed by ligamentous fibres to the 
margin of the fenestra ovalis. The space enclosed between the crura 
and base of the stapes, is naturally closed by a thin membrane. A 
very small muscle, called the stapedius, (to be shortly described) is 
inserted into the neck of the stapes. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 299 

The auditory ossicles are connected with and suspended from the 
surrounding bones by delicate ligaments. 

One such suspends the malleus from the wall of the tympanum, 
and the incus is similarly suspended, while the stapes is connected 
by ligament with the margin of the fenestra ovalis. 

There are two very small muscles * connected with the auditory 
ossicles — the tensor tympani and the stapedius. 

The tensor tympani muscle arises from a pointed process which 
projects from the free margin of the septum of the bulla as it 
curves upwards at the posterior wall of the tympanum. This 
process is sometimes small, sometimes rather long and pointed. 
The muscle then runs forwards and is inserted into the processus 
muscularis of the malleus. 

Beyond the origin of the tensor tympani the septum curves 
forwards and upwards and is lost on the promontory a little beyond 
the fenestra ovalis. 

The stapedius muscle arises from a more or less deep pit above 
the fenestra ovalis. It descends almost vertically to be inserted into 
the neck of the stapes. 

The mucous membrane of the tympanum is continuous, through 
the Eustachian tube, with that of the pharynx, and like it, is clothed 
with a ciliated epithelium, except where it lines the tympanic mem- 
brane. That membrane is, moreover, coated on either side by other 
membranes, being lined within by the general lining of the tympanic 
cavity, as it is coated without by the membrane of the external 
auditory meatus. 

The internal ear or special auditory part of the organ of hearing 
is a membranous structure enclosed in an excavation of the petrous 
part of the temporal bone called the bony labyrinth. This laby- 
rinth consists of three parts, a central chamber, the vestibule, con- 
nected with a part called the cochlea in front, and behind, with 
another made up of three semicircular canals. 

The vestibule is a somewhat pyramidal cavity, the front part of 
the inner wall of which abuts against the bottom of the internal 
auditory meatus and is pierced by numerous small foramina, 
which admit the filaments of the auditory nerve. At the front of the 
lower part of the vestibule is the opening which leads to the cochlea, 
while the posterior end of the vestibule shows the four openings of 
the three semi- circular canals. The outer wall of the vestibule is 
perforated by the fenestra ovalis, which, in the dry skull, opens into 
the tympanum. 

The cochlea (Fig. 138, a, c) is conical, and has the general form 
of a limpet shell, with its base directed towards the internal auditory 
meatus. The cone consists of a spiral tube which tapers as it 
recedes from its base, winding round a central column (the modiolus), 
the tube being incompletely divided by a lamina of bone, the lamina 

* The origins and insertions of these muscles have been carefully verified by 
Mr. Alban Doran. 



300 



THE CAT. 



[CHAP. IX. 




spiralis which projects out from the modiolus towards the opposite 
wall of the tube, except at its apex. It makes three revolutions 
and one quarter of a revolution round the modiolus, its course 
being from left to right in the right ear and from right to left in 
the left ear. 

The two divisions of the tube, incompletely separated by the 
lamina spiralis, are termed " scalce." 

The lower of these is called the scala tympany and it commences 

at the fenestra rotunda. The 
other division, called the scala 
•vestibuli, commences at the ves- 
tibule, with which it freely com- 
municates. 

The SEMICIRCULAR CANALS 

are bony tubes extending 
upwards and backwards from 
the vestibule from the four 
openings already mentioned 
as existing in the posterior 
part of that cavity. 

The tubes describe about 
two-thirds of a circle each, 
and may have one end dilated 
into what is called an ampulla, 
the cavity being considerably 
increased where such dilata- 
tion exists. The three canals 
receive different names, accord- 
ing to their positions. 

The superior vertical semi- 
circular canal (Fig. 138 a, c 3 ) . 
arches upwards and somewhat 
backwards as well as inwards 
from the outer side of the 
skull. It is the presence of 
this canal which causes a 
prominence on the upper part 
of the inner surface of the 
petrous part, of the petrous bone, just above the cerebellar fossa. The 
more anterior and outer end of this arch is the one that dilates into 
an ampulla and opens by a distinct aperture. Its posterior and 
inner end joins with the upper end of the arch next to be described, 
the two opening into the vestibule by a common aperture. 

The posterior vertical semicircular canal (c 2 ) arches backwards 
and slightly outwards, its upper end starting from the vestibule 
from an aperture common to it and to the inner end of the superior 
vertical semicircular canal. Its lower end opens into the vestibule 
in common with the adjacent end of the external or horizontal semi- 
circular canal. This last canal arches backwards and outwards and 



C2 



Fig. 138.— Bony Labyrinth and Auditory 
Ossicles (enlarged). 

Bony labyrinth of the right ear, extracted 
and reversed in position, its hinder end 
being placed forwards, and its upper margin 
downwards. 

c. Cochlea. 

c 1 . External horizontal semi-circular canal. 

c 1 . Posterior vertical semi-circular canal. 

c 3 . Anterior vertical semi-circular canal. 

f l . Fenestra rotunda. 

P. Fenestra ovalis. 

m. Ampulla;. 
Malleus. 

as. Articular surface of head. 

n. Neck. 

I. Lamina. 

pg. Processus gracilis. 

pm. Processus muscularis. 

pb. Processus brgvis. 

emn. Manubrium. 
Incus and orbiculare. 

o. Crus longum. 
Stapes. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 301 

opens into the vestibule by a distinct aperture, after dilating into an 
ampulla close to the fenestra ovaiis (,/ 2 ). Its other end joins, as 
before said, with the adjacent part of the posterior vertical semi- 
circular canal — the two opening into the vestibule by a common 
aperture. 

Within this osseous labyrinth is the true essential part of the 
organ of hearing, namely, the membranous labyrinth (Fig. 137), 
which is a very complex, closed sac, corresponding generally in figure 
with the osseous labyrinth within which it floats. It floats because 
the osseous labyrinth encloses ft fluid called the perilymph, which 
fluid surrounds the membranous labyrinth, which itself encloses 
another fluid called the endolymph. Both these fluids are slightly 
albuminous, and the former, the perilymph, is secreted by a delicate 
membrane of connective tissue, with a layer of epithelium, which, 
lines the osseous labyrinth and has no communication with, the 
lining of the tympanum (being cut off from that cavity by the 
membranes which close the fenestras) though more or less continued 
into the aqueducts. 

The membranous labyrinth consists, like the osseous labyrinth, of 
three divisions ; 1, that of the vestibule ; 2, that of the cochlea ; 
and 3, that of the semicircular canals. 

That part of the membranous labyrinth, which is enclosed in the 
vestibule, consists of two sacs connected by a narrow bent tube 
(which extends into the aqueductus vestibuli) and containing within 
them small crystals of carbonate of lime, called otoliths or otoconia. 
The more posterior of these sacs is called the utricle, and it is into 
this that the membranous semicircular canals open by four apertures, 
corresponding with those of the osseous semicircular canals. The 
other sac is termed the saccule, and a delicate tube proceeding 
from it extends to and connects it with that part of the membranous 
labyrinth which extends into the cochlea. 

The lamina spiralis of the cochlea has its free edge connected with 
the opposite wall of the spiral tube by a membrane which completes 
the separation of the two scalae except at their summit, where they 
communicate by a small opening called the helicotrema. The mem- 
brane which thus completes the partition between the scala) is 
called the basilar membrane. Another delicate membrane, called the 
membrane of Beissner, proceeds obliquely upwards from the lamina 
spiralis to the outer wall of the tube diverging in its course from 
the basilar membrane, and so cutting off a triangular canal from 
the region above the lamina spiralis. This triangular canal is 
called the canalis membranacea (or scala media), and it is connected 
by a minute tube (the canalis reuniens), with the saccule of which it 
is a continuation — forming as it does the second or cochlear part of 
the membranous labyrinth, and being filled with endolymph. Thus 
the canalis membranacea ascends the cochlear spiral between the 
two scalaB — the scala tympani ascending from the fenestra rotunda 
to the apex, and there communicating with the descending scala 
vestibuli, which ends in the vestibule. 



302 THE CAT, [chap. ix. 

A very peculiar organ lies in the floor of the canalis membranacea, 
which organ is termed the organ of Corti. It lies upon the 
basilar membrane, and is covered above by a delicate lamina, the 
membrana tectoria. The latter separates the organ from the cavity 
of the canalis membranacea with its contained endolymph. 

Thus this organ, with the basilar membrane below it and the 
membrana tectoria above it, forms a thickened floor to the relatively 
wide canal of the canalis membranacea. The organ itself consists 
partly of nucleated cells with stiff hair-like processes, partly of 
epithelial cells, and partly of two rows (one inner and one cuter) of 
tough rods (compared with cartilage in consistency), so leaning 
against each other as to enclose beneath them a minute triangular 
space between them and the basilar membrane. This long double 




Fig. 139. — A pair of Rods of Corti in side view, highly magnified. 



ir. Inner rod. 
er. Outer rod. 



The nucleated protoplasmic masses at the feet 
of the two rods are also shown resting on 
the basilar membrane. 



series of rods has been compared to the keys of a piano, which they 
to a certain extent resemble. Thus it may be said that each fibre 
of the organ of Corti consists of two filaments joined together so as 
to form an angle open downwards. Cells bearing hair-like fibres 
and epithelial cells are' placed on each side of this double range of 
rods, and beneath the inner cells (between the inner bases of the 
rods and the basilar membrane) are certain nucleated particles of 
protoplasm. 

The membranous semicircular canals occupy about one- third 
of the space enclosed by the bony canals in which they are suspended, 
and they dilate into ampullae there where the osseous semicircular 
canals so dilate. The lining of epithelium exhibits cells, which each 
sends forth hair-like processes projecting into the endolymph. 

The auditory nerve, after entering the meatus auditorius in- 
ternus, divides at the bottom of that canal into two bundles of minute 
fibres, which pass through the cribriform plate and are distributed 
to the vestibule and cochlea. 

The vestibular nerve sends twigs to definite parts of the utricle, 
of the saccule, and of each of the three ampulla?, and most probably 
ends by becoming continuous with the cells bearing hair-like pro- 
cesses, which exist in that part of each of these cavities which is so 
supplied. 

The cochlear nerve enters the base of the modiolus, and thence 
radiates to the scala media, and most probably ends by becoming 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 



303 



continuous with the cells hearing hair-like processes, which have 
been described as lying beside the rods of the organ of Corti. 

Thus here again — as in the organs of sight, smell, and taste — the 
ultimate structure which ministers to special sense is a system of 
rod-like filaments proceeding from spheroidal cells. 

Apart from the special, function of the ear — hearing — the various 
accessory structures serve the following 
purposes in aiding that function : the 
pinna serves to collect the sonorous 
waves, by its prominences and ex-» 
cavations, and to direct them towards 
the aperture of the meatus externus. 
This collecting process is greatly aided 
by the muscles, which enable the pinna 
to be turned in various directions. At 
the bottom of the meatus, the sonorous 
waves act upon the tympanic membrane, 
the vibrations of which are conveyed 
by the auditory ossicles across the tym- 
panum to the fenestra ovalis and so to 
the perilymph, and, finally, through 
the walls of the membranous labyrinth, 
to the hair-like processes projecting 
into the endolymph of the ampulla?, 
and to those of the organ of Corti. The 
vibrations of the rods of the last named 
organ doubtless intensify the vibratory 
action, as do the otoliths enclosed within 
the utricle and sacculus. 

The Eustachian tube places the air 
inside the tympanum in communication 
with the exterior, and so prevents undue 
tension. 

The stapedius and tensor tyrupani 
muscles tend by their contraction to 
tighten the tympanic membrane and 
that of the fenestra ovalis, and so to 
moderate the effect of too great sound. 
Thus the labyrinth, with its fluid con- 
tents, can be affected either by aerial 
waves through the meatus, tympanum, 
and fenestra ovalis, or through the bones 
and solid structure of the head. 

§ 27. Certain marked analogies 
exist between the ear and the eye, with 

certain noteworthy differences. Both are protected by skull bones, 
but the ear much more completely so. Both are protected by external 
folds of integuments furnished with muscles — the pinna and the 
eyelids. Both are supplied by a nerve of special sense, which enters 




Fig. 140. — Diagram of the Audi- 
tory Epithelium assd the mode 
of termination of the Xerves 
of the ampull.e. 

c. Columnar epithelium. 

sp. Spindle-shaped cells, each support- 
ing an* auditory hair, h. 

b. Basal supporting cells. 

n. Two nerve-fibres, passing through 
the layer of membrane (called the 
tunica propria) immediately be- 
neath the epithelium, to join the 
plexus in the epithelium. 
I. Limit of the membrane beneath 
the epithelium. 



304 THE CAT. [chap. ix. 

them through a foramen — the internal auditory meatus and the 
optic foramen. Both contain two internal fluids enveloped by proper 
membranes — the perilymph and the aqueous humour, and the 
endolymph and the vitreous humour. Both have a muscular 
apparatus to regulate the organ according to the quantity of special 
influence brought to bear upon it — the muscles of the ossicles and 
of the iris. Both have the action of the special influence intensified 
by contained hard parts — the otoconia and the lens — and, finally, 
both have their nerve of special sense expanded and ending in 
minute filaments on the innermost membrane of their respective 
structures. 

§ 28. The functions or the nervous system of the cat are 
activities the existence and nature of which can be ascertained only : 
(1) by more or less complex inferences deduced from what human 
beings can by self-consciousness learn as to their own affections, 
feelings and cognitions ; (2) by conversation ; (3) by the observa- 
tions of pathology ; and finally (4) by what can be ascertained as to 
other creatures by means of experiments upon different animals. 

Such inferences and observations show us that not only muscular 
motion and sensation depend upon nervous influence, but that even 
such functions as respiration, digestion, secretion, and excretion, 
are similarly modified, and that the circulation through the body of 
the nutritive fluid is greatly acted on— acclerated or retarded — by 
the same influence. 

For the perfect performance of all the nervous functions the 
integrity of the whole nervous system is a generally necessary 
condition. Nevertheless, partial mutilations of different regions 
of that system produce very different results, proving that all parts 
have by no means the same activity, but that different parts have 
different functions, and that some parts are much more necessary 
than are others to the maintenance of healthy life. When the 
destruction of any part of the nervous system induces the cessation 
of some function, the fact of that cessation does not indeed prove 
that such part is the very organ of such function, but it certainly 
shows that the non-destruction of such part is a sine qua non for its 
performance. 

Although we find that the powers of sensation and motion are so 
mixed up in ourselves that, when the body is entire, the existence 
of the latter involves the occurrence of the former, while any inten- 
sity of the former (sensation) produces almost inevitably some amount 
of the latter (motion) ; nevertheless observation and experiment 
prove that in abnormal conditions, either can occur without the 
other ; and the parts which minister to sensation alone or only to 
motion, are severally named sensory or motor parts of the nervous 
system. 

Our consciousness makes plain to us that we not only feel, but 
that we have very different kinds of feelings. Apart from ordinary 
common sensation, apart from feeling as to temperature and from 
visceral feelings, and feelings due to muscular action and the 



chap, ix.] NERVOUS SYSTEM AND OMGANS OF SENSE. 305 

exertion of effort, there are those special activities we know as 
sight, smell, hearing, and taste, the special senses, each absolutely 
peculiar and incapable of merging the one into the other. Finally, 
our consciousness shows us that accompanying these various states 
of activity, there may be either one or other of two accompanying 
conditions which we call respectively pleasure and pain. 

Certain phenomena which excite the activity of nervous tissue are 
called stimuli. 

These stimuli may be mechanical (as tickling, scratching, pinching, 
cutting, &c), or thermal (the application of heat or cold, producing 
a feeling of thermal change), or chemical (the application of various 
irritants), or electrical (causing a variation in electrical currents),* 
or finally, stimuli, natural to nervous tissue, and originating in end 
organs. These natural stimuli may be of two kinds ; they may be 
either (1) special (those which affect the organs of special sense, as 
light, sound, &c.) ; or (2) psychical, i.e., the presence of certain 
sensations, emotions, or cognitions. 

The presence of any of these stimuli must be of course without 
effect, unless the nerves acted on by them be in a certain state of 
excitability or impressionability — or, as it is sometimes termed, 
neurility. The long-continued excitation of a nerve will blunt, and 
ultimately will for a time destroy its power of action. A too pro- 
longed repose also diminishes and ultimately destroys its impression- 
ability, and may at last lead to its transformation into adipose 
tissue — a change which may also ensue if a nerve be separated from 
its nervous centre while yet remaining within the body. 

We have seen that nervous tissue is of two kinds, fibres and cells, 
and the activity of the tissue seems also to be of two kinds, namely, 
conduction (or an activity which conducts influences along nerves), 
and a more positive kind of activity, comparable with the explosion 
of a mass of gunpowder, to whi<:h a train of the same material has 
conducted a potent influence. It is the fibres which serve as the 
agents of conduction, and the cells of the grey matter are commonly 
supposed to produce the more positive kind of activity by some 
special powers of receptivity and reaction which they possess. A 
familiar example of this conduction and suddenly- active result is the 
application of a heated substance to the skin, with the result of its 
sudden withdraw-al from such substance through the conduction of 
some influence inwards from the skin to the source of the motor 
energy of the muscles, which then produce such recoil. Nerve 
action is altogether invisible. There is no, as yet observed, visible 
indication of the active state of a nerve analogous to the shorten- 
ing of a muscle which indicates myological activity. 

What is the nature of this nervous activity (apart from its 
results of motion or feeling, or secretion), is a matter of pure 
speculation. I. It has been compared with the action of electricity, 

* The resistance of nerves to electrical I versely as in the direction of their 
conduction is five times as great trans- I length. 



306 THE CAT. [chap. ix. 

of which it has heen deemed a special form. IT. It has been, and 
is by many, supposed to be merely one form of physical force — a 
mode of motion — specially transformed by the molecular structure of 
the matter through which it passes. III. It has been, and is by 
many, deemed to be a special kind of vital force peculiar to nerve 
substance. 

As to the first hypothesis, the slow rate at which the nerve 
impulse travels is alone sufficient to refute it. Whereas light 
travels at the rate of 40,000 miles in a second, and electricity, along 
a wire, at the rate of 462,000,000 feet per second — nervous influence 
appears to pass but at a rate varying from 80 to a little above 
200 feet in a second. Again, the interposition of a piece of wire 
between the cut ends of a bisected nerve does not serve to convey 
the nervous influences, and cold diminishes, instead of increasing, 
nervous activity. Moreover, bruising a nerve impedes its action ; 
but no similar effect could be produced on a wire serving for the 
conveyance of electricity. Moreover, the intensity of nervous action 
increases according to the length of the nerve it traverses, which is 
no property of electrical conduction. 

As to the second supposition — that nervous activity is merely one 
condition of physical force — it is but one form of the error which 
would explain all vital action as physical, in spite of the manifest 
impossibility of explaining generation, to say nothing of sensation in 
any such way. But one special hypothesis of the kind is that 
which views nervous conduction as the serial change of hypothetical 
nervous molecules from one physical condition to another, nerves 
being supposed to be made up of parts capable of being easily made 
to pass to and fro from one physical state to another — as a series of 
bricks set on end, may be alternately erected and thrown down, the 
falling of one inducing the fall of' its neighbour, and thus carrying 
on serially an impulse initiated at one end of the series. If such a 
conception is of any utility, as a working hypothesis to elucidate 
nervous physiology, there can be no objection to its use, but it must 
not be supposed to afford any real explanation. 

As to the third supposition — that nervous activity is a peculiar 
vital force — it is again no real explanation, though it is perhaps the 
most appropriate expression of the facts. It is manifest that the 
living body is capable of varied activities, and that its several parts 
exercise functions of different kinds. It is then little more than a 
truism to say that nervous tissue is the seat of nervous force. It is 
unquestionable that its integrity and stimulation are the conditions 
sine qua non for the manifestation of all the highest animal activities, 
while different degrees and kinds of injury inflicted on it result in 
different degrees and kinds of impairment of such activities, and, 
when carried beyond a certain point, end in the destruction of all 
vital activities whatever — even of the merely vegetative or organic 
activities. Nervous activity then is the vital activity of a living 
organism as it energizes in its nervous system. But the conception 
of a particular kind of vital force must stand or fall with the con- 



chap, ix.} NERVOUS SYSTEM AND ORGANS OF SENSE. 307 

ception of force itself, of which so much has heen made hy popular 
teachers of our day. Force, indeed, has been, and. is, constantly 
spoken of as if it were a substance ; as if indeed, it were the only 
substance. But to plain minds, as well as to followers of tbe highest 
philosophy — that of Aristotle — that which exists, as manifested to 
our senses, is the external world of visible, audible, tangible, sapid 
or odorous substances, which substances indeed possess many active 
powers. Force is in reality but an abstraction ; it does not exist 
either for our senses or our reason apart from substances, and is the 
name applied to the activities of such substances considered abstractedly 
from the acting substances themselves. A living body is a special 
substantial whole made up of parts, and both the whole and its parts 
have various active powers, and the active powers of animals, 
energizing through the nervous system are really what is meant by 
the abstract term " nervous vital force." 

§ 29. We may now pass to the consideration of the functions of 
the different parts of the nervous system. Before doing so, however, 
it should be observed that certain conditions are necessary for the 
continued exercise of all nervous activity. 

Thus the temperature of the body must be moderate, certainly not 
less than about 72°, or more than about 120°. The nervous tissue 
must also be adequately supplied with blood. This blood must be 
sufficient/?/ oxygenated, and also devoid of poisonous matter, such, e.g., 
as that with which it becomes charged from a cessation of the renal 
secretion. Finally, the continuity of the more important nervous 
structures must be maintained. 

§ 30. The functions of the spinal nerves are manifestly 
both sensory and motor, according to their distributions and con- 
nexions. If one of these nerves be divided and the cut end of its 
distal part be irritated, motion ensues in the muscles to which such 
nerve is distributed, but no pain ensues from such irritation. If, on 
the other hand, the cut end ol its proximal part be irritated, pain is 
caused, but not motion. If the posterior root of a spinal nerve be 
alone severed, the parts supplied with twigs from such nerve only 
lose their sensibility, but their power of motion remains. If, on the 
other hand, the anterior root of a spinal nerve be alone divided, then 
the parts supplied by such nerve are paralyzed as to motion, but 
nevertheless retain their sensibility. 

It has therefore been concluded that all the nerves conveying 
influence inwards, and centrally (called afferent nerves, and giving 
rise to sensation), pass through the posterior roots of the spinal 
nerves exclusively, and that the fibres which convey motor 
influence outwards and peripherally (called efferent nerves), pass 
through the anterior roots of the spinal nerves exclusively — the two 
sets being mingled at and beyond the point of junction between the 
roots, but sensory and motor fibres being distributed in the ramifica- 
tions of each spinal nerve. It has been further assumed that the 
nerves themselves neither feel nor initiate motion, but that both 
feelings and motor impulses arise in the grey matter of the nervous 

x 2 



308 THE CAT. [chap. ix. 

centres, with which the internal ends of the efferent and afferent 
fibres —internal end organs— are connected. 

This opinion has been reinforced by the fact that after severe 
injuries to the spinal cord, parts supplied with nerves which take 
origin below such injury, become deprived both of sensibility and of 
the power of voluntary motion, while irritation of the cut surface of 
the proximal part of a divided nerve in a limb stump may produce 
a sensation, which feels as if it took place in parts which no longer 
exist — as, e.g., in the toes, when the leg has been amputated. But 
in fact these phenomena are susceptible of another explanation, and 
one which admits the belief that sensation occurs there where it 
appears to occur— and not far away in the central part of the 
nervous system. For as the completion of the electrical or magnetic 
circuit is necessary for electric or magnetic discharge, so a certain 
integrity of the nervous structure is necessary for the result of 
nervous action in motion or sensation, even though such sensation 
really take place at that part of the body where it seems to be felt. 
When, however, the integrity of the nervous structures is impaired, 
the motor or sensitive nervous activity is correspondingly impaired, 
and the occurrence of non-natural and abnormal sensations might 
be d priori expected to arise under such non-natural* and ab- 
normal structural conditions. The occurrence of abnormal and 
more or less delusive feelings after structural injury, by no means 
proves that sensation is not peripheral under normal conditions. It 
only proves that while nervous integrity is a sine qua non of normal 
sensation, it is not a condition for the occurrence of all sensation, 
but admits of the occurrence of feelings of an abnormal and 
accidentally delusive character. 

It has also been very often assumed and supposed that the dis- 
tinctions between the functions of nerves (i.e., whether they are 
sensitive or motor) is due to some special endowment of the nerves 
themselves, and not merely to the connexions which they may 
happen to have. Now, however, it seems more probable that most, 
if not all, nerves are essentially similar as regards their own intrinsic 
powers, but that different nerves have practically different functions, 
because their connexions are different. According to this view, any 
nerve going from a nervous centre to a gland must have for its 
function the promotion of secretion ; any nerve going from a centre 
to a muscle must have for its function the production of motion, 
and any nerve going from a peripheral end organ to a centre must 
have for its function either the promotion of sensation or reflex 
action. 

Whether this view be or be not correct, nerves, as we actually 
find them, are either centripetal or centrifugal in their action, and, 
as a rule, nervous influence can only be propagated in one direction 
in any particular nerve. It may be that some nerves are inhibiting 
ones, i.e., they are nerves which proceed from centres to the vicinity 
of other nerves, and, by their influence, check or neutralize the 
actions of the latter. 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 309 

§ 31. The so called functions of particular nerves are then partly 
learned through their distribution, partly through experiments, and 
partly by the very simplest observations. Those of the cranial 
nerves, for instancy which minister to special sense, are plainly 
and obviously distinguishable from all others. Mechanical, 
stimulation of the optic or auditory nerves does not produce pain, 
but only certain sensations either of light or noise. Division cf 
the various cranial nerves causes paralysis or insensibility, or both, 
to the parts they supply, in accordance with their distribution and 
what has already been said as to their several functions. 

Thus, division of the seventh nerve causes distortion of the mouth 
from paralysis of the muscles of the face, except those supplied by 
the fifth, nerve. 

The integrity of the pneumogastric nerve is needed for the experi- 
ence of the sensations of oppression from want of air, of irritation in 
the air passages, of hunger, thirst, &c, as also for the due performance 
of the functions of the parts supplied by it. Thus its division paralyses 
the movements of the stomach (so that food is only digested at its 
surface,) and diminishes its secreting power, as well as that of the 
liver, and renders deglutition impossible — finally even producing 
suffocation. Yet it accelerates the action cf the heart, which is, on 
the contrary, impeded or stopped by irritation of the pneumogastric, 
so that it seems that this nerve acts normally as a check on the 
heart's action. Division of the spinal accessory nerves paralyses 
the action of swallowing and also of the laryngeal apparatus and so 
destroys the voice, though the respiration action (being under the 
influence of the pneumogastric) continues. Division of the hypo- 
glossal nerves, of course, paralyses the tongue. A short summary 
of the functions of all the cranial nerves has been already * given. 

§ 32. The function of the spinal cord is commonly considered 
to be merely a conductor of both sensitive influence to the brain and 
of motor (especially of voluntary) influence from it ; and this is no 
doubt true in a certain sense. Thus it is true that the transmission 
of some influence up it to the brain is a necessary condition to tho 
experience of sensation, and that the transmission of some influ- 
ence down it from the brain is a necessary antecedent to voluntary 
motion ; but it does not by any means follow, as is often supposed, 
that on this account sensation and voluntary action are to be 
considered as really localized in the brain because of the necessity 
of the intervention of that organ in order to their experience. 
Though, no doubt, what are practically the centres for complicated 
motions, are in the brain. 

With this proviso, we may treat, in the ordinary way, of the paths 
which these influences seetn to follow in traversing the spinal cord. 
It is almost certain that both are predominantly situated in the white 
fibres. It appears from recent experiments that both motor and 
sensory impulses ascend and descend through the lateral columns, the 
special functions of the anterior and posterior columns being unknown. 

* See ant", § 16, p. 275. 



310 THE CAT. [chap. ix. 

If the spinal cord be cut through, it is impossible for the injured 
animal either to feel any irritation which may be applied to parts 
the nerves of which take origin below the division, or by any 
voluntary effort to move any such parts. Nevertheless movements 
of such parts may be produced by stimuli applied to them, without 
the occurrence of either conscious sensation or voluntary effort. 
Such unconscious movement in response to unrecognized stimuli is 
called reflex action. This shows that the cord itself must be a 
centre capable of initiating responsive action — of turning, as it were, 
unfelt sensitive impulse into involuntary motor impulse. It does, 
in fact, that which the brain does ; but does it, at least when thus 
mutilated, without the accompaniment of any perceived sensation. 
This kind of action is also called automatic or excito-motor, and it is a 
curious fact that responsive movements of this kind are more 
energetic than they would normally be, owing possibly to the spinal 
centres being entirely devoted to the reflex action, and not at all by 
the transmission of influence to the brain. 

But reflex actionmay take place in the uninjured condition, as during 
sleep or under the influence of chloroform. Even w r hen awake the 
sudden and involuntary withdrawal of the foot from an irritating 
object is an instance of essentially the same kind of action, though 
since sensation here intervenes, such an action is spoken of as 
sensori-motor, and is not exclusively due to the action of the spinal 
cord. But, in fact, all action is " reflex" in .the widest sense of that 
term, i.e., including sensori-motor action. For all animal actions 
which do not result from unfelt stimuli (internal or external) result 
from felt stimuli. 

Sensations are capable of radiation or transference, as where 
disease in the hip may produce pain in the knee-joint, or as, during 
neuralgia, when pain proceeds from the part supplied by one branch 
of a nerve to parts supplied by other of its branches. 

§ 33. As to the functions of the medulla oblongata, it appears 
to transmit and transfer influences in essentially the same way as 
the spinal cord does — as when irritation of the stomach produces 
headache, or when pain in one tooth results in pain in the corre- 
sponding tooth of the other side. The sensory impulses proceed 
through the restiform bodies (which are extremely sensitive to touch) 
and the motor ones, through the anterior pyramids. The division 
of either pyramid results in motor paralysis, but, owing to the 
decussation of their fibres, a paralysis of the side of the body opposite 
to that of the division, supposing the cut to be made above the place 
of decussation. Similarly, paralysis of the opposite side of the body 
follows from destruction of one half of the encephalon above such 
decussation. The function of the olivary bodies is unknown. 

The medulla is the seat of many reflex actions, such, e.g., as 
sneezing, coughing, closing the eyelids, swallowing, and the respira- 
tory actions. After the insensibility produced from concussion of 
the brain or from chloroform, food placed far back in the mouth will 
be swallowed and respiration will be still carried on. Indeed, in 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 313 

the frog, respiration will continue if the medulla be left intact, even 
though the brain and the spinal cord have both been removed, while 
destruction of the medulla oblongata immediately arrests it. Injury 
to a limited region of the floor of the fourth ventricle causes sudden 
cessation of respiration and instant death in warm-blooded animals. 
Thefactthatso many cranial nerves have their deep origins in thispart 
of the cerebro-spinal axis, sufficiently explains the extensive character 
of its excito-motor and sensori-motor activities. Indeed this part 
may be supposed to serve as the organ of the common sense, i.e., of 
that sense by which the several senses come into relation one with 
another and are felt as diverse modifications of one sentient being. 

§ 34. The functions of the pons varolii are, at least, in part 
similar to the conducting functions of the medulla — the central grey 
and white portions of both being continuous. Animals deprived of 
both cerebrum and cerebellum, but with the medulla and pons 
intact, remain motionless if undisturbed, but if disturbed move 
themselves into postures of stable equilibrium, which they seem 
incapable of doing if the pons be removed, although the medulla 
be left. 

If the fibres passing from the pons to the cerebellum on one side 
be cut through, the injured animal's body begins to rotate towards 
the injured side, the eyeball of the injured side moving downwards, 
while the eye of the opposite side rolls convulsively. 

The functions of the corpora quadrigemina are closely con- 
nected with the sense of sight, since not only their destruction causes 
blindness and immobility in the iris, but they often waste after 
atrophy of the eyes. The destruction of one side of this structure 
causes blindness in the opposite eye. 

The optic thalami are also thought to be concerned in sight, yet 
this sense may persist after their destruction. They are by many 
supposed to form the anterior termination of the sensory tract of the 
cerebro-spinal axis and to be the organ of the common sense, which 
sense, however, may perhaps be more fitly attributed to the medulla 
oblongata. There is evidence that they have to do with the power 
of supporting the body on the limbs, as this power may remain after 
the destruction of the corpora striata, but ceases after the removal 
of the optic thalami. 

The corpora striata are similarly deemed by many to form the 
anterior termination of the motor tract of the cerebro-spinal axis 
and to convey downwards from the cerebrum impulses resulting from 
the grouping of images attributed to the cerebral hemispheres. 

The cerebellum has had a variety of functions assigned to it, 
but its real office is still unascertained. It has been supposed to 
co-ordinate the muscular movements, or to specially direct the 
muscles of the eyes, or to be the organ of space relations generally, 
or finally, to be the seat of the sexual emotion. 

On the whole it appears probable that the cerebellum ministers to 
complex and co-ordinated muscular movements. Such a conclusion 
seems to result from pathological facts and vivisections : animals 



312 THE CAT. [chap. rx. 

being unable to rise after they have been thrown down if the cere- 
bellum has been removed. The greatest caution however is needed 
in concluding from negative facts, and, as yet, it cannot be safely 
affirmed what is the true and special function of this remarkable 
organ, the predominant connexions of which are with the spinal 
cord and not with the brain. 

§ 35. The true functions of the cerebrum are also far from 
being satisfactorily known. It has been generally regarded as the 
organ of cognition, and it is abundantly proved that the destruction 
of both the cerebral hemispheres puts an end to all manifestations 
of intelligence, so that this view may be to a certain extent accepted. 
Recent experiments also tend to make the opinion probable, 
that certain of its surface regions are related to the five special 
senses. But similar experiments have also shown that the electrical 
stimulation of different parts of the cerebrum will cause different 
movements. Such movements, however, may after all be due in 
fact to the necessarily induced irritation of more deeply seated 
parts by the unavoidable diffusion of currents. It seems, however, 
to be fully proved that the cerebrum has a great deal to do with 
motion, and is an important motor centre. It may be that by its 
sensory and motor connexions it ministers to that sense of effort, 
and to those feelings of different kinds and degrees of effort which 
are often spoken of (perhaps unfortunately) as the " muscular 
sense," and to feelings of movement. For the present, however, 
the true functions of the cerebrum cannot be said to be known, 
although they afford abundant matter for more or less ingenious 
speculation. 

§ 36, The functions of the sympathetic system relate to the 
performance of the organic functions of the body, and especially 
regulate the activities of the viscera. 

On account however of the multifold and intimate connexions 
of this system with the cerebro- spinal system, it has been as yet 
impossible certainly to determine what activities are truly under 
the control of the sympathetic. Normally its actions do not give 
rise to sensation, though, in unhealthy conditions pain may accom- 
pany them. The presence of ganglia and afferent and efferent 
fibres renders it in the highest degree probable that some sympa- 
thetic nervous action is of the reflex order, — complete in itself and 
more or less independent of the cerebro -spinal system. The action 
of the sympathetic, by stimulating the secretion of glands, may call 
into play instinctive actions and stimulate emotions. Both secretion 
and nutrition are greatly influenced by the sympathetic, but this may 
be, but indirectly, owiug to alteration of the calibre of the arteries by 
the influence of the vaso-motor nerves. Such of the arteries as are 
supplied from any particular branch of the sympathetic become 
dilated when that particular branch is cut. It is supposed that the 
action of the vaso-motor nerves (derived partly from the sympathetic, 
partly from the cerebro- spinal system,) is to keep the muscular coats 
of the arteries moderately contracted, and that, therefore, when the 



chap, ix.] NERVOUS SYSTEM AND OBGANS OF SENSE. 313 

action of these nerves is paralysed (as, e.g., by division) the arteries 
they supply dilate, and in this way increased sensibility and secreting 
power is promoted by the greater supply of blood thus induced. 
Some physiologists, however, explain this dilatation as a positive 
instead of a negative action. 

The nervous sytem is, as we have seen, bilateral, but between the 
two halves of its central part there are, as we have also seen, 
numerous transverse commissural structures and decussating fibres. 
The correspondence of function with structure in this respect is 
shown by those cases, already given, in which injury or stimulation 
of one side of the central nervous system produces effects on the 
opposite side of the body. That the cerebral hemispheres are each 
capable of carrying on all the activities requisite for cognition is 
proved by the fact that the destruction of one does not necessarily 
even impair cognitive activity. It may seem strange that with the 
presence of a double organ of such a special nature, processes of 
cognition and feeling should be, as they are, single ; but, in fact, 
there is no greater wonder in cognizing singly by two similar hemi- 
spheres than in seeing singly through two similar eyes. 

§ 37. A phenomenon that may not unfitly be here noticed, is 
sleep, since during it the central nervous system, or part of it, 
undergoes a temporary suspension of its activity. It is the cerebrum 
and the sensory centres which thus periodically intermit their action. 
Certain parts, however, of the nervous centres never sleep, as is the 
case with those which govern the unceasing respiratory actions, as 
also those parts of it which minister to all the functions of vegetative 
life. Yet, although thus continued, the frequency of the respiratory 
and circulating movements, diminishes, and the temperature of the 
body is consequently lowered. The quantity of the blood in the brain 
is by some persons supposed to be diminished during sleep. Before 
the daily period of repose is reached, the activity of the nervous 
system has generally already been so taxed that it no longer 
responds with thorough readiness to stimuli. With the assumption 
of an attitude of rest, and with the closing of the eyes, this 
torpidity increases, till it ends in more or less complete repose. 
Sleep gradually counteracts the effects of previous activity, and in 
consequence the readiness to respond to stimuli becomes progres- 
sively greater as sleep continues, till the occurrence of some very 
slight exciting cause suffices to awake the dormant animal. Apart, 
however, from any exhaustion from fatigue, the cat generally falls 
asleep with remarkable readiness at any hour (when not disturbed 
by hunger or passion), as soon as it has become quiescent. 

§ 38. Before concluding this account of the functions of the 
nervous system by saying what remains to be said of the several 
special senses, certain remarks may be made with respect to sensa- 
tion IN GENERAL. 

Sensations are of two classes, external and internal. The former 
are produced by the agency of external bodies, the latter by the 
body itself. They may both exist simultaneously, as when one part 



314 THE CAT. [chap. ix. 

of the body presses on another. For the experience of sensation at 
all the presence of a nerve is a necessary condition, and for the 
exercise of special sensations we require special conditions of special 
nerves. Sensations are not momentary, but persist more or less as 
after effects, as may readily be perceived by first looking at the sun 
or' any very bright object, and then looking at any duller object, 
when a dark spot, or spectrum, will be visible, resembling in shape 
the bright object previously looked at. 

Frequent and continued repetition of the act of sensation diminishes 
through exhaustion the sensitive power, but moderate, habitual 
exercise of any faculty of sense tends to develope and perfect it. 

The special semitice faculties are each sui generis, nor can one 
merge in another, nor all in any common power of sensation. Thus, 
before any special sense can exist or act, it must be present poten- 
tially, i.e., it must be innate. Each special sense is elicited in a 
manner totally unknown. If we count up all the number of sensa- 
tions which differ in kind, their number will be seen to be consider- 
able. Thus we have perception of change of temperature, the sense of 
internal effort and resistance (the so-called muscular sense), the sense 
of hunger, thirst, fatigue, sickness, and finally we have the two very 
peculiar phenomena — pleasure and pain, and the faculties, touch, 
taste, smell, sight and hearing, commonly called the special senses 
par excellence. All the special sensitive faculties, however, may be 
deemed to have a relation of similarity with touch, and in each, as 
we have seen, delicate nervous filaments are exposed in some special 
manner to receive a stimulation of a peculiar kind. 

The feelings above enumerated are felt in different parts of the 
body, nor are those persons who deny that they are really felt where 
they seem to be felt, able to establish that they are actually felt in 
any other place. 

As to pleasure and pain, they are feelings of a special and un- 
analyzable kind which accompany (either one or the other) in a 
greater or lesser degree all other feelings. The healthy performance 
of the bodily functions, when felt at all, is pleasurable. Hindrances 
to, or irregularities in, their performance are commonly painful. 
With many exceptions and variations, it may be said that pleasura- 
ble sensations tend to guide to actions which are profitable to the 
organism, and painful ones to deter from such as are injurious. 

The sense of touch in its simplest form is a feeling of contact ; 
by intensifying this feeling we get feelings of resistance, density, 
hardness, softness, &c. By employing movement in addition, size, 
distance and figure become appreciated, and the nature of surfaces, as 
e.g., their roughness, smoothness, &c. 

The delicacy of touch, as .perceived by the skin, varies much in 
different parts, as we have seen. These differences are doubtless 
related to the differences in the number of nerve fibres supplied to 
the different parts. 

Impressions received by touch become associated with other ones, 
and cohere in more or less complex aggregations, which may be 



chap, ix.] NERVOUS SYSTEM AND ORGANS OF SENSE. 315 

retained in the sensitive memory, cohering and being retained the 
more firmly, the more frequently they are repeated. 

The sense of taste can only he exercised upon matters in a state of 
solution. It is closely connected with the sense of smell, insomuch 
that various flavours, which are commonly supposed to be perceived 
through taste, become imperceptible if no use be made of the sense 
of smell. Sight even has its effect upon taste, as the relish for various 
pleasant tasting substances may be diminished by darkness. This sense 
is very capable of education, and pleasurable feelings can be induced 
by perseverance with respect to substances which are at first distaste- 
ful. One kind of taste will for a time paralyze the power of 
appreciation of other flavours, while, per contra, certain tastes (e.g., 
wine and cheese) reciprocally stimulate the intensity of gustatory 
sensations they respectively give rise to. After-tastes are sometimes 
observed, such as a taste of sweetness following the intensely bitter 
taste of tannin. 

The sense of smell needs for its exercise the presence of some 
influence in the air drawn in through the nostrils, the Schneiderian 
membrane being moist and tbe olfactory nerves in a normal condi- 
tion. Olfactory impressions do not persist as Jong as do those of 
taste, and of course much less than those of touch, but they are very 
"delicate, a tt.ooV/o-o-o P ar t °f musk being perceptible when mixed with 
common air. The sense of smell can be strengthened by use, and it 
tends to act both as a deterrent and also as a guide to what is 
attractive to the organism. Odours become easily associated in 
memory with sensations of other kinds, so that a recurrence of a 
smell will often recall the latter. Smell may be considered as guard- 
ing respiration, as so many noxious atmospheric conditions are 
attended with disagreeable odours. 

The sense of hearing gives information as to the intensity, quality, 
and direction of sounds. It has been a widely received doctrine 
that the nerve-branches supplied to the semi-circular canals enable 
us to appreciate the direction of the sounds heard, while the cochlear 
filaments serve to make known the qualities of sounds ; these are 
purely speculative opinions, and their truth cannot be relied on. 

The sense of sight, as regards the mechanism of its organ, has 
been already explained. It remains but to speak of the curious fact 
that the co-existence of inverted images on the back of two eyes 
produces but a single perception of an external world which is not 
inverted. This phenomenon has been explained by attributing the 
exercise of sight not to the eyes themselves, but to certain of the 
grey masses within the cerebrum, or to the corpora quadrigemina. 
It is, however, to say the least, no less inexplicable that such interior 
grey masses should be the seat of sight, than that the retina itself 
should be that seat. It is objected that irritation of the cut optic 
nerve produces a sense of light, and it is thence argued that percep- 
tion of light must he interior, as also that in persons who have lost 
their eyes, diseased conditions may produce spectral illusions. But 
to such objections it may be replied (analogously to the reply before 



)16 



THE GAT 



[CHAP. IX. 



made as to a similar objection with respect to the spinal nerves), 
that we willingly admit the possibility that the excitation of a large 
fragment of the organ of vision, may produce a fragmentary sensible 
perception, as also that the grey matter of the interior roots of the 
organ plays an important part in eliciting the act of sensation, but 
these admissions do not render it any less rational to suppose that 
when the whole organic circuit is normal and complete, the animal 
really sees both in and with its eyes.* 

As to the perception of distance and direction, it may well be that 
the perceptions of all the special senses besides touch, i.e. y colour, 
sound, taste and smell, can only be localised, not by the nerves of 
special sense, but by the help of those branches of the fifth nerve 
— a nerve of ordinary sensation — which go to those organs. 

The functions of the nervous system may then be summarized as 
follows : — 

It presides over, stimulates and regulates the alimentary, circu- 
lating, respiratory, glandular and reproductive processes of the body ; 
it induces appropriate response to stimuli which are unfelt (reflex 
action) and to felt stimuli (sensori-motor action) ; it regulates all 
the muscular contractions which result in motion, and finally it 
ministers to all those modifications of " feeling " and all those 
complex associations and complications of feelings known as imagi- 
nation, memory, emotion and cognition, to which reference will again 
be made in the chapter on Psychology. 



* As the different end-organs of the 
retina perceive different colours, either 
each such end-organ must be devoted 
to the perception of one colour only, or 



else each must he capable of stimula- 
tion by stimuli which are qualitatively 
different. 



CHAPTER X. 



THE DEVELOPMENT OF THE CAT. 



§ 1. By " the development of the cat " is signified the sum of those 
rapidly succeeding morphological and physiological changes which 
commence the life history of the animal. They are changes of great 
importance and significance — changes in the very nature of the 
creature undergoing them, as well as in the forms and relations of 
the different parts of the body which successively come into existence. 
Each individual of the species upon attaining majority, naturally 
develops one or other of those two products which have been described 
in the eighth chapter — ova and spermatozoa. 

We may consider the formation of these products as the culmina- 
tion of the individual's development, and we may consider the 
conjunction of those products as the initiation of another individual's 
life. The series of changes, then, which make up the cat's life 
history, is a series which tends (the requisite conditions being 
supplied) to return in a cycle. . The impregnated ovum becomes, as 
we shall see, an embryo ; the embryo, a foetus ; the foetus, a kitten ; 
and the kitten, a cat, destined to give rise to, or to fertilize, another 
ovum like that with which this cycle of changes began. By the 
cat's "development," then, should be meant the entire sum of 
changes it undergoes, from its condition as an impregnated ovum 
till maturity ; but practically it has come to mean (as above said) 
that early part of the process which takes place up to, and till 
shortly after, birth. Thenceforward the changes which ensue are 
less changes in the forms and relations, than in the dimensions of 
parts ; and the process of " development " becomes mainly a process 
of " growth." 

§ 2. But the ovum undergoes certain initial changes, even before 
impregnation takes place, which changes may nevertheless be re- 
garded as a part of the developmental process. Such changes, how- 
ever, as well as some others (especially those of the earliest stages of 
development after impregnation), have not been actually witnessed in 
the cat's ovum. Nevertheless, the analogies of animals generally, on 
the one hand, and of animals nearly allied to the cat on the other, 
make it possible to infer what those changes in all probability are. 

The ovum having attained to the condition already described in 



318 



THE GAT. 



[CHAP. X. 



the eighth chapter,* with its yelk, zona pellucida, germinal vesicle 
and spot, the first change preparatory to impregnation is the rupture 
of the Graafian follicle. Having been cast forth from that follicle 
and entered the Fallopian tube, the ovum spontaneously begins the 
developmental process itself. Its nucleus, or germinal vesicle, ap- 
proaches the surface of the ovum, and its outline becomes irregular or 
obscure. Having reached the surface, one or two portions of its sub- 
stance, called polar vesicles, are extruded through it from the ovum. 
The remnant of the germinal vesicle then returns towards the centre 
of the ovum, and constitutes the central, or so-called "female " pro- 
nucleus. It probably contains a nucleolus, and the protoplasm of the 
ovum becomes radiately striated around it. 

All is ready now for the act of impregnation! 

§ 3. The spermatozoa having advanced to the ovum (for by their 
vibratile action they can make their way up the uterine cornua and 
Fallopian tubes), no sooner meet with it, than they plunge into 
its outer transparent coat, and one spermatozoon (possibly, f but not 
probably, more than one) actually bores its way through, and plunges 
its head into the substance of the ovum. That substance itself, how- 
ever, is not altogether passive, for a small prominence may arise 
from its surface to meet the incoming spermatozoon. Immediately 
this contact has taken place, the outermost layer of the ovum's pro- 
toplasm may separate itself off as a distinct membrane, and so bar 
the way to the entrance of other spermatozoa. 

The head of the spermatozoon having thus entered the ovum, it 
constitutes there a second peripheral or " male " pronucleus. This 
advances towards the centre of the ovum, the protoplasm of which 
assumes a radiate arrangement round it. Then the two pronuclei 
are attracted towards each other and meet and fuse into a single 
body called the " first segmentation nucleus (Fig. 141, A). This 
nucleus has thus been formed by two corresponding parts from 
the male and female organisms respectively. For the female 
pronucleus is a portion of the nucleus of a germ cell, the whole 
of which has become modified into the ovum, while the male 
pronucleus is a spermatozoon, which is a part of the nucleus of 
the original sperm-cell, which divided to form spermatozoa. We 
have therefore in the first segmentation nucleus, what must rank 
as a true nucleus of complex nature and diverse origin — an origin 
from two equivalent and complementary parts. 

§ 4. The next step in the process of development is that known as the 
segmentation of the yelk, or vitellus, L e., of the protoplasm of the 
ovum. The first segmentation nucleus gradually elongates, becomes 
medianly constricted, and divides into two secondary segmentation 



* See ante, p. 250. 

+ There is as yet much divergence of 
opinion on this matter, and some ob- 
servers even maintain that the entrance 
of more than one spermatozoon is an 
occasion of monstrosity in the embryo. 



The reader will find a full statement and 
discussion of these views in Mr. F. 
Balfour's pxeellcnt Treatise on Com- 
parative Embryology, vol. i., 1880, 
p. 67. 



CHAP. X.] 



TEE DEVELOPMENT OF THE CAT. 



319 



nuclei, and the protoplasm of the ovum also divides, arranging itself 
around each secondary segmentation nucleus. The two halves are 
not quite equal in size. One, larger and more transparent (Fig. 
141, B, e) is the ectodermic or epiblastic sphere, the other (i) is the 
endodermic or hypoblastic sphere. Each sphere again subdivides, 
and the same process is repeated with each subdivision, there being 
thus four spheres, or cells, derived from the primitive epiblastic 
sphere, and four from the primitive hypoblastic sphere. One of 
these latter now assumes a central position (Fig. 141, C). The 
process of division is then continued, but unequally, the cells derived 
from the epiblastic sphere dividing more rapidly, and therefore be- 
coming smaller than these from the hypoblastic sphere. Moreover 




Impregnated ovum, with a single segmenta- 
tion nucleus. 
h. External envelope. 
z. Zona pellucida, with spermatozoa. 
n. Segmentation nucleus. 
y. Protoplasm or yelk of the ovum. 



Fig. 141.— Yelk*Segmentation. 

B. Ovum, with the yelk divided into two 
cleavage cells, each with its nucleus. 

e. Epiblastic cleavage cell, 
i. Hypoblastic cleavage cell. 

C. Fourth segmention into eight cells— four 
epiblastic and four hypoblastic. 



the epiblastic cells come to surround and enclose the hypoblastic 
cells, save, perhaps, at one point where the hypoblastic cells may 
appear at the surface (Fig. 142). The mass of cells, however, forms 
a solid whole. There is no central cavity. Soon, however, a clear 
space appears, and liquid forms between the mass of hypoblastic cells 
and the epiblastic cells (Fig. 143, A), save at one part where the 
two sets of cells adhere together. This process rapidly continues as 
the ovum grows, the interspace becoming' wider and wider, till at last 
we have a relatively large sphere of very small epiblastic cells, against 
the inside of one part of which the aggregation of small hypoblastic 
cells is flattened out, so that we have a double stratum of cells, consist- 
ing of a single layer of hypoblastic cells beneath a single layer of epi- 
blastic cells (Fig. 143, B). In other words, we have two cellular 
membranes — an epiblast and a hypoblast — the epiblast investing 
the whole ovum within the vitelline membrane, the hypoblast under- 
lying only a portion, though a considerable portion, of the epiblast. 
The cellular membrane thus investing the ovum, and derived from 
the segmentation of the yelk, is called the blastoderm, and the 
whole structure is the blastodermic vesicle. That part where the two 



THE CAT. 



[CHAP. X. 



membranes coexist is the germ area, or gastrodisc. In the central 
portion of this, a third membrane soon makes its appearance (Fig. 

144). This is the mesoblast, 
and is thought to be derived 
from the hypoblast,* by sub- 
divisions of the cells of the 
letter. The three- layered part 
of the gastrodisc is a much 
thickened part of it, and is 
called the embryonal area, for it 
is here that the embryo arises. 
Up to this point the matter 
which is eventually to become 
the body of a ca/t shows no re- 
semblance to any animal what- 
ever. It is but an aggregation 
of cells of protoplasm arranged 
as just described, and is rather 
comparable with some very 
lowly organised fungus-like plant 
than with anything we ordi- 
narily understand as an animal. 
§ 5. It is in the midst of the embryonal area that the first sign 
of the cat which is to be, is made manifest by the first appearance 




Fig. 142.- -Longitudinal Section through the 
Axis of the Ovum, in which the Epiblastic 
Cells (e) have almost surrounded the 
Hypoblastic ones (i). 

d. Central cell. 

o. Hypoblastic cell, occupying the interspace 
left at one point by the epiblastic cells. 




Fig. 143. 



A. Commencing separation between the epi- 
blastic and hypoblastic cells. 
e. Epiblast. 
t. Hypoblast. 
k. Cavity formed by the separation. 



B. Completion of the process, and formation of 
a germ area, or gastro-disc, of two layers — 
one (e) of epiblastic cells, the other (i) of 
hypoblastic cells. 



of the embryo. The first indication of the embryo is the appear- 
ance of a longitudinal depression or furrow, termed the medullary 
groove (Fig. 145), and it is the sign of the appearance of the most 
important and central of all the organs of the future animal, for in 



* In a paper read before the Royal 
Society on March 23, 1876, Mr. E. A. 
Schafer describes the formation of a 
membrane in the cat's ovum between 
the epiblast and hypoblast. This mem- 
branous follicle he named membrana 



limitans hypoblastica. The fact of its 
presence favours the view according to 
which the mesoblast is derived from the 
epiblast. See Pro. Roy. Soc, vol xxiv., 
plate 10. 






chap, x.] THE DEVELOPMENT OF THE CAT. 



321 



this groove is laid the foundation and commencement of the cerebro- 
spinal axis, which, as we have seen, is the supreme and dominating 
organ when that body has attained maturity, and which is thus formed 
from inflected epiblast. The groove becomes enlarged at its anterior 
end, in the situation of the future- brain (Fig. 145, C), while the 
lateral margins of the whole groove grow up (as the dorsal plates or 




Fig. 144. 



-Diagram of Section through: the Germ Area of a Mammal at Right Angles 
to the surface. 



e. Epiblast. 
i. Hypoblast. 



m. Mesoblast, or third layer. 
k. Cavity of the vesicle. 



lamince dorsales) bend over and ultimately meet together above, 
thus changing the groove into an elongated, hollow cylinder; the 
central cavity of which is the precursor of the canalis centralis, of 
the spinal cord, and of the third and fourth ventricles of the cerebro- 




Fig. 145.— First appearance of the Embryo, as shown by the Medullary Groove. 



In A the germinal area is pyriform, and the 
primitive groove occupies two-thirds of the 
narrow hinder end. 

In B the gioove is elongated, and th< middle 
line and line closely surrounding it indicates 
the rising up of the laminae dorsales or 



medullary plates on each side of it. 
In C the embryo is seeu somewhat expa 1 ded 
towards each end. 

at. Transparent area. 

ao. Opaque area. 

mp. Medullary groove. 



spinal axis as well as of the iter between them — the enlargement at 
the cephalic end assuming the form of three successive dilatations or 
vesicles. Beneath the longitudinal groove a cellular rod becomes 
developed, extending forwards as far as the hinder end of the front 
cephalic vesicle and backwards to the end of the medullary groove. 
This rod is the notochord, or chorda dorsalis, and occupies the 
place of the future bodies of the vertebrae, the soft substance of the 
intervertebral discs of the adult being its persistent remnant. 



322 



THE CAT. 



[chap. X. 




The notochord appears to be formed from the mesoblast, but it 
may be really of hypoblastic origin. While these changes are in 
progress, a depression appears close to both 
the cranial and caudal ends of the embryo — 
the head and tail folds — and these extending 
along each side of the embryo, the latter 
comes to look somewhat like a small boat, 
keel upwards, upon the surface of the ovum, 
surrounded by the groove or depression 
thus formed. The parts of this surrounding 
groove between the head and tail folds are 
called the lateral folds. At the outer margin 
of this depression the surface begins to grow 
up all round the embryo as a prominent 
circumvallation. Meanwhile the mesoblast 
extends outwards and downwards on each 
side of the embryo, so forming what are 
called the ventral plates and lamina centrales 
(Fig. 147, A, Iv). As each ventral plate 
descends it splits into two secondary laminae 
(one external, the other internal) called re- 
spectively the somatopleure and splanchno- 
pleure (Fig. 147, B, so and sp). The distal 
part of the somatopleure, where it extends 
beyond the embryo into the circumvallation 
before mentioned, ascends with that circum- 
vallation around the groove about the embryo 
to form the amnion, as explained below. The 
splanchnopleure adheres closely to the hypo- 
blast adjoining the yelk. That part of the 
somatopleure which does not grow upwards, 
comes ultimately to form the whole of the walls 
of the body and the limbs (Fig. 147, D). The splanchnopleure forms 
the alimentary canal and structures adjacent to it. The cavity between 
the somatopleure and splanchnopleure is the precursor of the future 
peritoneal cavity (Fig. 147, D,p), and the innermost layer of the former 
and the outermost layer of the latter form respectively the parietal and 
the visceral layers of the peritoneum. Thus we t have the body cavity 
formed by a spontaneous longitudinal splitting of the mesoblast on each, 
side. The further extension of the somatopleure gives rise to the 
amnion. It is formed thus : the somatopleure'of the mesoblast, carry- 
ing the epiblast with it, rises up on all sides of the embryo at the 
outer margins of the groove round the embryo (around the head, tail, 
and lateral folds in the circumvallation before mentioned) and as each 
ascending part is double, an extension of the primitive peritoneal cavity 
becomes thus continued upwards on all sides of the embryo. A chamber 
is at the same time thus gradually formed between the outer surface 
of the embryo and the innermost (more and more bent over) surface 
of this ascending, circumferential double layer, which thus gradually 



Fig. 146. — Embryo more ad- 
vanced, SEEN SIMILARLY 
above with part of the 
Blastoderm attached. 

The medullary groove is not 
yet closed over, but at 
the head end it is par- 
tially divided into the 
three central vesicles ; 
the hinder end shows a 
smaller enlargement. Six 
primordial vertebrae (pv) 
are to be seen on each 
side. 

so. Epiblast. or upper layer. 
Lower layer of the blas- 
toderm. 



sp. 



CHAP. X.] 



TEE DEVELOPMENT OF THE CAT. 



323 



grows up around and over the embryo. This up-growth continues 
until the ascending folds of the circumvallation meet and coalesce 
abovo the embryo, and so form a completely closed sac above it. 
This sac is tbe amnion (Fig. 148, 2 , 3 , 4 J. The cavity enclosed 
by it is, of course, the same as the cavity of the " chamber " above 




INITIAL STAGES OF DEVELOPMENT. 

Fig. 147. — Embryo seen in Transverse Section, showing formation of Somatopleure and 
- Splanchnopleure, and of the Peritoneal Cavity. The part of the Somato- 
pleure WHICH ASCENDS BEYOND THE EMBRYO IS NOT REPRESENTED. 



mg. Medullary groove, 
e. Epiblast. 
m. Mesoblast. 
h. Hypoblast. 
Id. Laminae dorsales. 
Iv. Laminse veutrales. 
in. Notochord. 
nc. Neural canal. 
sp. Splanchnopleure. 
so. Somatopleure. 
%. Intestine. 
u. Umbilical vesicle. 

ug. Prominences in which primitive urinary 
and sexual glands arise. 



p. Peritoneal cavity. 
me. Mesentery. 

A. Embryo, with the mesoblast as yet unspl 

B. Mesoblast split into somatopleure and 

splanchnopleure, and with an incipient 
separation between the intestine and th 
subjacent umbilical vesical. 

C Further closing off of intestine from um- 
bilical vesicle. 

D. The body cavity (or peritoneal cavity) com- 
pletely enclosed by somatopleure, while the 
part of the splanchnopleure between th 
intestine and superior part of the embryo 
has become attenuated into a mesentery (m 



mentioned as being " gradually formed between the surface of the 
embryo " and the " more and more bent over surface " of the 
ascending circumvallation. The embryo lies in the amnion as in a 
water-bed. For though at first this sac is very small, it subse- 
quently enlarges and becomes filled with a certain fluid called the 
liquor amnii. As the ascending folds are (as before said) double on 
all sides (Fig. 148, 3 ) it follows that upon their coalescence a double 
sac is at first formed. The amnion is the inner of these two sacs. 
The sac external to it (formed of the outer layers of all the folds) 
disappears by coalescing with the chorion, or outer envelope of the 
ovum, within which of course all the changes here described take 
place (Fig. 148, 4 ). As the primitive peritoneal cavity was con- 
tinuous with the space enclosed between the two layers of the 
ascending folds, it follows that (upon the completion of the amnion) 
there comes to be for a time a communication (over the back of the 
embryo and above the amnion) between the two sides of the peri- 
toneal cavity. This space is occupied by a more or less fluid or 
gelatinous substance (Fig. 148, br). This communication is, how- 
ever, soon cut off by the descent and in growth of that part of the 
somatopleure which forms the side-walls of the body of the embryo. 

Y 2 



324 



THE CAT, 



[CHAP. X. 







Fig. 148. — Five Diagrammatic Vertical Sections through the Long Axis of a Maturing 
Mammalian Ovum, to show the formation of its egg-membranes. 



In Figs. 1—4 the section passes through the 
middle of the embryo. In Fig. 5, it passes 
a little on one side, so that the left side of 
the embryo can be seen. 

1. Ovum in which the chorion has begun to be 

formed, with the blastoderm (and rudiment 
of the embryo) within it. The whole germ- 
vesicle consists of epiblast and hypoblast, 
in the germ area, niesoblast (m) has also 
appeared. 

2. Ovum in which the head and tail-folds have 

contracted the umbilical aperture towards 
the yelk-sac; while the ascending circum- 
valliition is seen rising at either end to form 
the amnion. Here, then, the embryo is 
beginning to separate from the germ- 
vesicle (ds) . 

3. The amniotic folds being completed, have 



met in the dorsal region ; the umbilical 
opening is more contracted, and the allan- 
tois (at) has begun to sprout. Here we see 
the double sac forming above the embryo, 
the inner part of which alone becomes the 
amnion. The intestinal canal (dd) is begin- 
ning to be distinctly formed. 
Here the inner amniotic sac or true amnion 
is detached from the outer or false amnion, 
which has disappeared by coalescence with 
the inner surface of the chorion. The 
cavity of the amnion is more distended, and 
the yelk-sac (ds) has become smaller and 
pedunculated. The allantois (al) projects 
into the space between the amnion, chorion 
and yelk-sac ; and the villi are larger, and 
have begun to ramify. 



CHAP. X.] 



THE DEVELOPMENT OF THE CAT. 



325 



Meantime, during the development of the amnion, another structure, 
of great importance to the embryo, is being formed. This is the 
allantois (Fig. 148, 3 & 4, at), which buds forth from the mesoblast 
beneath the hinder portion of the incipient abdomen. It soon attains 
a large size, and becomes supplied with blood-vessels for a purpose 
to be presently described. 

While the amnion and allantois are thus being formed, the side 
walls of the embryo are closing in by the median junction ventrally 
of the somatopleure of one side with that of the other side, and 
the splanchnopleure of one side with that of the other side, thus 
enclosing — between the inner layer of conjoined splanchnopleures — 
a space which is the future alimentary canal (Fig. 147, C and D). 
This is at first closed in front and behind, and everywhere, except 
at one ventral point, where it remains open, and in connexion with 
the remains of the yelk, which, with its enveloping membrane, is 
termed the umbilical vesicle (Fig. 147, C, u). 

On each side of the medullary groove and notochord a series of 
quadrate thickenings appear, termed protovertebrce (Fig. 146, pv), 
which are the first signs not only of the vertebrae, but also of the 
muscles and nerves connected with them, to all of which they 
give rise. Inflections of the epiblast about the incipient head, lay 
the foundations of the organs of special sense, while an epiblastic 
inflection at each end of the alimentary tube forms respectively the 
buccal and anal chambers. In the mesoderm, immediately beneath 
the anterior end of the chorda, the blood and blood-vessels become 
developed, and one vessel, tubular and rythmically contractile, lays 
the foundation of the heart. Blood-vessels at first go to and fro 
between the umbilical vesicle and the heart to absorb nutriment 
from the yelk, but subsequently these are outstripped in development, 
and so replaced by other vessels which go to and fro between the 
allantois and the heart. Thus the great blood-vessels have at first a 
very different course and arrangement from that which they ultimately 
attain. About the alimentary canal, the liver arises, while the trachea 



More advanced embryo, showing the proto- 
vertebrse, visceral arches, and rudimentary 
limbs. The allantois has grown out to the 
inside of the chorion, and conveyed vessels 
to it. The villi are more complex. The 
umbilical vesicle is small, and connected 
with the embryo by a long duct. In the 
embryo cat, however, this vesicle is spindle- 
shaped, and of considerable size, and the 
duct is short. 

e. Embryo. 

a. Epiblast. 

m. Mesoblast 

i. Hypoblast. 

am. Amnion. 

Tcs. Head-fold. 

ss. Tail-fold. 

ah. Cavity of amnion. 

as. Amnionic sheath of the umbilical 
cord. 

Teh (Fig. 1). Hollow of the germ-vesicle, 
which becomes (ds) that of the yelk- 
sac. 



dg. Duct leading from the alimentary 
canal to the yelk-sac. 

df (Fig. 3). Lining of umbilical vesicle or 
yelk-sac. 

dd. Dorsal wall of intestine. 

d. Yelk or vitelline membrane, or primi- 
tive chorion. , 

Permanent chorion, with which not 
only the outer layer of the amnionic 
folds (sh), but also the allantois, has 
combined. 
Allantois. 

r. Space, filled with fluid, between the 
amnion and chorion. 

lili. Region of the heart and pericardial 
cavity. 

vl. Wall of the thorax in the region of the 
heart. 

d' (Figs. 1, 2, and 3); sz (Fig. 4) and 
ch z (Fig. 5). Villi of chorion. 

sh (Fig. 3). Outer layer of amniotic fold, 
which, in Fig. 4, has coalesced with 
the inner wall of the primitive 
chorion. 



ch 



al 



326 



THE CAT. 



[CHAr. x. 



an 




and lungs grow out from that canal ventrally. The renal and sexual 
organs arise close to the bifurcation of the ventral laminae into the 
somatopleures and splanchnopleures, and the limbs bud forth as rounded 
processes, the distal ends of which subsequently grow out into digits, 
while the limbs themselves become flexed in reverse directions. On 

each side of the body, close behind 
the head, certain apertures ap- 
pear, which lead from the exterior 
to what becomes the pharynx. 
These openings are the visceral 
clef is, and their interspaces are 
the visceral arches. Almost all 
the clefts disappear before birth. 
The formation of these various 
organs will be detailed subse- 
quently, but their relations to the 
three primary layers, from which 
the whole of them are built up, 
may be summarized as follows. 
The epiblast gives rise to the 
epidermis of the skin, the ner- 
vous centres, and the organs of 
sense. The hypoblast forms the 
epithelium of the alimentary 
canal, except its two ends, and 
of the glands which open into 
it. The mesoblast forms the in- 
ternal skeleton, the muscles, connective tissue, peritoneum and 
pleurae, and the vascular and secreting organs generally. It forms, 
therefore, the great bulk of the cat's body. 

§ 6. During the whole process of development the germ is 
nourished by absorption. Within the Graafian follicle it profits by 
the cells of the discus proligerus and membrana granulosa, and when 
cast forth frorn its follicle into the cavity of the uterus it absorbs 
nutriment from the secretions of the uterine walls by processes, or 
villi, which grow forth on all sides from the surface of its chorion. 
It also feeds upon the contents of the umbilical vesicle, absorbing 
nutriment thence by the help of the vessels which there circulate, 
and which are at first of great relative size and importance. With 
*the development of the allantois, however, a new condition obtains. 
That organ is destined to convey out embryonic blood-vessels to the 
surface of the ovum, so that they may there be placed in intimate 
relation with the blood-vessels of a special, corresponding maternal 
structure, which is formed in the wall of the uterus around the 
circumference of the therein- contained ovum. 

While the ovum is undergoing the incipient stages of develop- 
ment, corresponding changes take place in the maternal structures. 
The presence of the impregnated ovum within the uterus is ac- 
companied by the growth, on the inner surface of that organ, of a 



Fig. 149.— Section through Cornu of Uterus, 

SHOWING THE TWO POINTS OF ATTACHMENT 
OF THE ZONARY PLACENTA, THE EMBRYO 
BEING REMOVED. 

pi. Placenta. 

m. Its maternal portion sending processes 

between. 
. Tufts projecting from chorion or membrane, 

enveloping embryo. 
re. The umbilical cord. 
am. Amnion. 
ut ut. Walls of the uterus. 



chap, x.] THE DEVELOPMENT OF THE CAT. 327 

soft tissue called the decidua, within which the young ovum imbeds 
itself, and from which it at first derives its nutriment. 

As the ovum grows, however, one portion of the decidua thickens 
and becomes highly vascular. This is called the decidua serotina 
(Fig. 149, m), and it forms a ring round that part of the uterine 
cornu in which the ovum lies. The adjacent part of the rapidly- 
enlarging ovum also becomes specially supplied with blood-vessels 
from the embryo contained within it, through the intervention of its 
already-mentioned allantois. Processes from the vascular ring of 
the chorion (Fig. 147, t) pass into recesses in the vascular ring of 
the uterus— the serotina decidua, arid the two parts form an in- 
separable interlacement called the placenta (Fig. 147,^/). The 
maternal and embryonic* blood-vessels, however, nowhere actually 
communicate, and therefore no intermixture takes place between the 
blood of the embryo and the blood of the mother. An abundant 
gaseous interchange, however, is effected between them, the blood 
of the embryo- taking oxygen from, and giving off carbonic acid gas 
into, the maternal blood. Thus the placenta is a temporary and 
indirect breathing organ for the embryo, which can breathe in no 
other way, lying, as it does, enclosed in fluid. 

As has been already said, the allantois, with its blood-vessels — 
called umbilical arteries and reins — stretches itself forth into and 
across the space within the ovum, till it arrives at the inner, surface 
of the chorion, where it expands, wrapping round the whole embryo 
with its amnion, carrying its vessels te the vascular portion of the 
chorion, and so contributing to form the placenta. The junction 
once effected, the arteries and veins connecting the foetus with this 
part of the chorion rapidly enlarge. The umbilical arteries convey 
the impure blood of the foetus to the placenta, where it is purified, 
as before said, and nourished by the influence of the maternal 
blood (the two fluids having but thin membrane between them), 
and is then returned to the embryo by the umbilical veins, which 
proceed back' along the allantois from the placenta. Meantime, 
while the embryo is thus enclosed in its amnion and nourished by 
its allantois, the splanchnopleure grows in on all sides in the way 
before mentioned, so as almost to separate the embryo from the 
remnant of the yelk in its sac — the umbilical vesicle. The stalk 
which connects this vesicle with the intestinal cavity of the embryo is 
short but slender. It is called the vitelline duct or ductus omphalo- 
entericus. The umbilical vesicle remains of rather large size as a 
transversely-elongated sac produced into two horn-like prolonga- 
tions. It lies between the amnion and the allantois. 

The structure which connects the embryo or foetus with the 
placenta is called the umbilical cord. This is made up mainly of 
the narrow part of the allantois (consisting of the embryonic or 
fcetal arteries and veins with connective tissue) with the vitelline 
duct, the whole being bound round and enclosed by a fold of the 
amnion extending down round it, and being thence reflected over 
the foetus (Fig. 147, vc). The umbilical cord is the sole channel 



THE CAT. 



[chap. X. 



through which nourished and oxygenated blood is conveyed to the 
foetus, and its importance continues till birth. The establishment of 
pulmonary respiration, however, and the acquisition of the power of 
taking nourishment by suction, do away with all need for the 
placenta, and, by consequence, for its stalk, the umbilical cord, 
which is gnawed across by the mother on the kitten's birth. The 




fig. 150.— fcetus in tjteb.0 (buefon and daubenton), showing the fcstus enveloped in its 
Amnion, and with its zonarv Placenta and spindle-shaped Umbilical Vesicle. 



a. Chorion. 

b. The zonary placenta. 
d. Umbilical vesicle. 

/, /. Its elongated extremities. 
g. The vitelline duct. 



h. The sac of the amnion 
7c. The foetus. 
The short umbilical cord is shown passing from 
the abdomen of the embryo to the placenta, 
and immediately giving forth its vessels, 
forwards and backwards, into the placenta. 



part left in connexion with the abdominal wall soon shrivels up, 
dries, and falls off, but a permanent mark of its place of attachment 
persists throughout life as the umbilicus or navel. 

Such being the form and arrangement of the foetal membranes 
and adjuncts, the embryo or fcetus itself gradually and in a round- 
about way assumes the image of the kitten in the mode already 
intimated, and which will be more fully explained in describing the 
development of the several organs. 

The period of gestation is fifty-five or fifty-six days. The ovum 
having by that time attained its full inter-uterine development, 
vigorous contractions of the muscular walls of the uterus ensue, 
while the os uteri dilates. The embryo is thus expelled from the 



chap, x.] THE DEVELOPMENT OF THE CAT. 329 

uterine cavity, and comes away, bringing with it a portion of the 
maternal part of the placenta, together with the foetal part, with 
which the maternal part is inextricably united. Thus the super- 
ficial part of the decidua serotina comes away, while its deeper part 
is left, with a torn and bleeding surface. Coincidently with the 
termination of gestation, the mammary glands take on functional 
activity and become ready to play their part in the post-natal 
development of the young. After the expulsion of the embryos, of 
which several are in general simultaneously developed, the uterus 
forms a fresh internal lining, while the thickness of its walls 
decreases by degeneration and absorption of a portion of its muscular 
tissue, which had so much increased in quantity during pregnancy. 

§ 7. It remains to consider seriatim, the development of the 
various tissues and organs of the body. 

All the various tissues and structures of the adult cat (connective 
tissue, cartilage, bone — all parts of the skeleton of course included) 
arise from the primitive fluid, granule, and cells of the fertilized 
ovum by a process which is called differentiation. This term, which 
is often used as if it were a real explanation, simply denotes the 
fact that the various parts arise not through external actions, which 
are but the concomitants and conditions of their origin, but by an 
as yet utterly inexplicable and innate power possessed by the primi- 
tive substance or matrix, within which the parts referred to, come 
(under the requisite external conditions) gradually to manifest 
themselves. Other terms relating to development similarly denote 
spontaneous and mysterious actions of the formative power, and are 
but convenient phrases for denoting the actions of such power, and 
not explanations of it. 

Such terms, for example, are segmentation — which denotes that a 
structure, primitively of one piece, spontaneously divides its substance 
into parts; vacuolation — denoting the spontaneous resolution of part of 
a more or less dense structure in such a way as to give rise to a cavity 
or cavities within it ; and fenestration — denoting that a solid structure 
has dissolved itself at one spot or more, so as to give rise to an 
aperture perforating it. When then the development of the tissues 
and parts of the body are herein described, the intention is but to 
state the order and mode in which they manifest themselves, the 
fact being distinctly recognized that an innate force is the real and 
efficient cause. 

The primitive almost fluid substance containing granules, which 
exists in the developing ovum, is known as protoplasm ; and proto- 
plasm is often spoken of as if it were a sort of primary organic material 
— a distinct kind of formed substance — from which all organisms arise. 
But the fact that the primitive substance of one animal or plant is 
not to be distinguished by any chemical or physical test we can apply 
from the primitive substance of another animal or plant, does not by 
any means prove that the two are really the same substance. It does 
not prove this identity, because of the very different results which 
are successively evolved in the two cases, as development proceeds. 



330 THE CAT. [chap. x. 

This ultimate diversity is amply sufficient to show that a real differ- 
ence existed from the first — a difference thus demonstrable to our 
reason, though not manifest to our senses. 

From the primitive substance of which the cat's ovum consists, all 
the ultimate constituent parts of its body are derived through the 
help of the cell formations , already described as the epiblast, hypoblast, 
and mesoblast. It has already been mentioned that the epiblast gives 
rise to the epidermis of the skin and to the nervous centres ; the 
hypoblast, to the alimentary epithelium; and the mesoblast, to the great 
mass of the body. But parts which are derived from one of these 
sources may acquire characters quite like those derived from another. 
Thus the linings of the two ends of the alimentary canal are (as has 
been said) formed from inflected epiblast, and epithelial structures 
(as in the lining of the vessels and of the peritoneal cavity) can be 
formed as well from the mesoblast as from the epiblast. 

All the tissues and organs of the cat's body are then derived 
from cells, and indeed they are doubly so derived, since the ovum 
before yelk segmentation begins, is a perfect cell — with its cell-wall 
(or periplast) and its nucleus (or endoplast), the latter being fur- 
nished with one or more nucleoli. Thus this cell begets the cells 
of the three layers of the embryo, and these latter cells beget all the 
tissues and organs which subsequently arise, and the great mass of 
them are begotten by the cells of the mesoblast. 

But though all the tissues have this ultimate cellular parentage, 
they by no means always retain a plainly cellular structure, as they 
severally arise from the primitive, or "indifferent " tissue of the 
mesoblast, and become definite connective, muscular or nervous 
substance, as the case may be. Sometimes they take on the form 
simply of a soft substance of one or another kind, within which 
nuclei are embedded at intervals. From analogy we may regard 
the parts of such substance which are adjacent to such nuclei as 
representing cells, the limits of which are severally indistinguishable. 

The five main constituents of the cat's body — (1) connective tissue, 
with its derivatives, cartilage and bone ; (2) epithelial tissue^ (3) 
blood; (4) muscular tissue ; and (5) nervous tissue — arise as follows : 

Connective tissue appears to arise in the embryo, partly as a jelly- 
like substance, or matrix, and partly as cells from the mesoblast, 
which though more or less separated by this substance, yet remain 
connected by processes which grow out in a radiating manner from 
them. The fibres of the tissue are by some observers described as 
arising within the protoplasm of the cells, those of adjacent cells unit- 
ing, while the parts of the cell not thus transformed persist as connec- 
tive-tissue corpuscles. Other observers, however, believe that the fibres 
arise, as an independent deposit, within the intercellular substance. 

Elastic tissue is said to be formed from other cells which grow out and 
branch, becoming connected with processes from neighbouring cells. 

Cartilage appears in its simplest condition (in the chorda clorsalis 
or notochord) as a mass of closely applied, thin-walled cells. The 
layer of the embryo from which these are derived, is (as has been 



CHAP. X.j 



THE DEVELOPMENT OF THE CAT. 



331 



said) not yet positively ascertained, but the other cartilages of the body 
are undoubtedly of inesoblastic origin. The walls of the primitive 
cartilage cells thicken and form the intercellular matrix, acquiring 
at the same time the special qualities of cartilaginous tissue. The 
thus-formed matrix may remain clear and structureless, or may 
become flbrillated, as in the case of fibro-cartilage. 

Bone is a substance which is never directly formed from the in- 
different embryonic tissue, but requires for its development the 
pre-existence of either cartilage or connective tissue. The process 
of its formation in these substances has been already noticed.* 

Epithelial tissue is the most distinctly and permanently cellular of 
all the tissues of the body, and it arises directly from the cells of 
the epiblast and hypoblast, with the exception of the endothelium 
of the vessels and pleuro-peritoneal cavity, and some other parts 
which are derived (as already said) from the mesoblast. The epen- 
dyma of the cerebral ventricles is the persistent epiblast of the lining 
of the medullary groove of the embryo. Ova and spermatozoa may 
be considered as special modifications of epithelial tissue. 

Blood appears to originate within cells derived from the meso- 
blast, f either by a multiplication of their nuclei and the acquisition 
of a red colour by the protoplasm around each nucleus, or else as a 
sort of deposit within the cells. However originating, the primitive 
corpuscles when formed become separated from one another by a 
process of vacuolation % within the cells. The cells then enlarge 
and send out processes which unite with those of other cells. The 
walls which separate the cavities of such united processes then dis- 
appear, so that their cavities communicate, and thus blood and blood- 
vessels are simultaneously formed. 

The primitive red corpuscles are nucleated, and larger than 
those which subsequently arise, which latter, together with the 
white corpuscles, seem to be formed mainly by the spleen, the 
nucleated red corpuscles disappearing and being replaced by the 
smaller, flattened non-nucleated corpuscles, during embryonic life. 

Muscular tissue, though by no means clearly cellular in its fully 
formed condition, is said to have a distinctly cellular origin, being 
formed by direct transformation of embryonic cells as follows : § the 
cells elongate and acquire an investing membrane and often pointed 
ends. The nuclei multiply, and the contained protoplasm of the cells 
gradually acquires its striated character. The investing membrane 
becomes the sarcolemma, and the scattered nuclei "become the 
corpuscles. The unstriped muscular fibres originate simply by the 
lengthening out and flattening of cells, which acquire pointed ends 
and an elongated nucleus. 

Nervous tissue is, as has been said, mainly derived from the epi- 



* See ante, p. 20. 

+ A perfect agreement has not yet 
been arrived at as regards their mode of 
origin. See Balfour, Quarterly Journal 
of Microscopic Science, July, 1873 and 



Schafer's Proceedings of the Eoyal 
Society, 1874. 

+ See ante, p. 329. 

§ See Wilson Fox, Phil. Trans., 1866. 



332 



THE GAT. 



[chap. X. 



blast ; but. although the nervous centres are thus formed, aud though 
the cranial nerves arise also as small invaginations of epiblast, yet 
the mass of nerves which permeate the body in all directions cannot 
be so^ derived, but must originate from mesoblastic tissue. The 
ganglionic cells or^ nerve corpuscles are doubtless derived from 
embryonic cells, which became transformed in nature and send forth 
processes (very generally) in the way described.* 
As to the nerve-fibres, they seem to be formed by the coalescence 




Fig. 151. — Longitudinal Section of an Embryo, showing the Incipient Vertebral 
Column with its Vertebral Centra and Spinous Processes. 



Cerebral hemispheres. 

Vesicle of the third ventricle. 

Mid-brain. 

Cerebellum. 

Medulla oblongata. 

, Notochord passing forwards through the 
bodies of the vertebrae into the basis cranii, 
and terminating in the head between the 
infundibulum and the pituitary body. 

The spinous processes of the vertebrae. 

The spinal cord. 

The pharynx. 

The heart. 

The liver. 

The stomach and intestine. 



cl. The cloaca. 

v. The urinary bladder and pedicle of the allan- 
tois. 

U, u'. The umbilicus, or root of the umbilical 
cord, containing the duct from the intestine 
to the yelk-sac, the pedicle of the allantois 
(or urachus), and the umbilical vessels. 

w. The Wolffian body, which appears as an 
elongated viscus, with many trans verse lines 
situated above and between the two letters, 
% and i ; whereof the left-hand i is placed 
upon the stomach, and the right-hand i on 
the large intestine close to the caecum and 
entrance of the small intestine. 



in linear series of spindle-shaped cells, and to be at first of the 
nature of pale or grey fibres, but afterwards, in great part, to acquire 
a medullary sheath and to become white fibres. 

§ 8. We may next consider the origin of the organs, and first the 
internal skeleton. 

The axial skeleton makes its appearance much earlier than 
the appendicular skeleton, inasmuch as its foundations are laid in 
the laminae dorsales bounding the medullary groove, and in the 
notochord as already described. The distinction of the axial skeleton 
into its vertebral and cranial portions is laid down from a very early 
period, since the enlargement of the anterior end of the medullary 
groove into the cerebral vesicles at once marks out the cranial part, 
a distinction rendered yet plainer by the non-extension of the 
chorda dorsalis forwards through it. 



* See ante, p. 255. 



chap, x.] THE DEVELOPMENT OF THE OAT. 333 

The earliest indication of the segmented condition of {he vertebral 
skeleton is the appearance of the quadrate masses of tissue, appear- 
ing serially in pairs behind the head — the so-called proto-rertebrce 
(Fig. 146, pv), or dorsal segments, already noticed as arising in the 
mesoblast on each side of the chorda dorsalis and medullary groove. 
The front part of the first of these bodies corresponds in position with 
the atlas, and each pair of dorsal segments gives rise, amongst other 
structures, to part of the bony spine. The dorsal segments do not, 
however, correspond w T ith the future vertebras, but each segment 
becomes transformed into : (1) the hinder part of one vertebra, (2) 
the anterior part . of the vertebra next behind, (3) the roots of a 
spinal nerve, and (4) the muscles and skin immediately connected 
with the vertebral parts so formed. Thus each primordial vertebra 
becomes ultimately segmented, wdiile each successive pair of such 
primordial vertebras ultimately coalesce, and so a different segmenta- 
tion is brought about .from that which appears at first ; the points of 
separation of the later segmentation, alternating with those of the 
earlier segmentation. The first dorsal segment of each side differs 
from those which succeed, in that when it becomes segmented, its 
anterior half has nothing in front wherewith to coalesce, and thus 
the atlas must be formed from half a primordial vertebra instead 
of being formed, like the other vertebras, from the hinder half of one 
primordial vertebra and the anterior half of the primordial vertebra 
next behind. 

Moreover, while the upper part of each dorsal plate becomes a 
segment of -dorsal muscle\ with its skin, the lower part undergoes a 
different change in its anterior (cephalic) and posterior halves. An- 
teriorly it gives rise to the root and ganglion of a spinal nerve. 
Posteriorly it gives rise to the transverse process of a vertebra or 
proximal portion of a rib. 

The inner part of each dorsal plate bifurcates as it extends 
inwards. One branch ascends in the dorsal lamina till it meets its 
fellow of the opposite side and so forms the foundation of the future 
neural arch. The other branch advances inwards above and below 
the chorda, and blends with its fellow of the opposite side to form 
the foundation of the central portion of a vertebral segment. Thus 
each permanent vertebra is the offspring of the parts of two adjacent 
primordial vertebras. Its neural arch, transverse processes, the 
proximal part of its ribs, and the cephalic portion of its centrum, 
are formed from the hinder end of one proto-vertebra, while the 
rest of its centrum and its spinal nerves are formed from the anterior 
(cephalic) end of the proto-vertebra next behind. 

This condition having been, as it were, laid down in soft tissue, 
transformations of parts of the structures thus formed, into cartilage, 
soon begin. 

Cartilage of the ordinary kind first invades the body of each 
vertebra and surrounds the chorda, encroaching on and constricting 
it at intervals, the chorda yet continuing a structure of large thin- 
walled cells enclosed in a fibrous sheath. Cartilage becomes also 



334 



THE CA1, 



[CHAP. X. 



deposited at intervals along each, dorsal lamina, forming cartilaginous 
neural arches which, however, do not for sometime fully unite together 
on the dorsal side of the myelon. < Cartilages also extend down in 
each ventral lamina as the cartilaginous predecessors of the ribs, and 
those of the thorax, by their median fusion in the mid- ventral line, 
lay the foundation of the sternum. N 

The third stage of vertebral development, or the ossification of 
the spinal column, begins to show itself as three (or four) ossific 
centres arising in each of the vertebrae. These centres are placed 
one in each lateral part (at the junction of the transverse process 
and neural arch), and the other, or third, in the centrum. This 
last is sometimes double at first. 

Besides these separate centres each vertebra, while immature, has 
certain epiphyses or temporary separate terminal ossifications. Thus 

the tip of each prominent process 
(neural spines, transverse and 
articular processes and the met- 
apophyses) has its epiphysis, 
and a thin lamina of bone is 
developed as an epiphysis on both 
the anterior and posterior sur- 
face of each centrum. The atlas 
ossifies from two lateral ossifica- 
tions, and one median one ven- 
trally placed. 

In the axis, in addition to the 
ordinary ossific centres found 
in other vertebrae, the odontoid 
process ossifies from two centres, 
placed side by side, which soon 
unite. There is also an epiphy- 
sis at the apex of the odontoid 
process, and one between it and 
the centrum of the axis as well 
as on the hinder surface of the 
latter. Thus the odontoid pro- 
cess ossifies as if it were, as in 
fact it is, the true centrum of the 
atlas vertebra. 

The ribs are ossified each from 
one centre, with an epiphysis for 
the tuberculum and another for 
the capitulum. 
In the cervical vertebra more or fewer of the transverse processes 
ossify, at least occasionally, from a distinct ossific centre in their 
ventral branch, a circumstance which tends to show (what is in fact 
the case,) that these double (or perforated) transverse processes are 
ribs with very short bodies. 

Similarly the sacral vertebrae have each a distinct ossific centre in 
each of their lateral masses. 




Fig. 152.— Diagram of Fgetus, showing 
the Visceral Arches and Budding Limbs. 
(It represents mainly conditions existing 
between the third and fourth weeks.) 
a. Prominence produced by incipient cerebrum. 
6. Prominence produced by region of third 
ventricle. 

c. Prominence by region of corpora quadrige- 

mina. 

d. Prominence produced by cerebellum. 

e. Prominence produced by medulla. 
al. Allantois. 

h. Heart. 

I. Liver. 

an. Incii>ient ear. 

oc. Incipient eye. 

na. Incipient nose. 

its. Naso-frontal process. 

mps. Maxillary process (from first visceral arch) 

laying foundation of upper jaw. 
1, 2, 3, 4. " Visceral arches ;" between them are 

the "visceral clefts." 



chap, x.] TEE DEVELOPMENT OF THE CAT. 335 

Tlie manubrium ossifies after the other segments of the sternum, 
■which seem each to ossify from one centre. 

§ 9. The development of the SKULL takes place in a specially 
circuitous manner, so that its eaily stages are strikingly unlike its 
mature condition. The first indication of the future skull is given 
by the expansion, before mentioned, of the anterior end of the 
medullary groove, which expansion, as has been said, becomes 
divided by two lateral constrictions (one in front of the other, on 
each side^ so that three rounded vesicles are formed lying serially 
one before the other. The notochord extends forwards to beneath 
the second of these vesicles, wnich bend down sharply in front of 
its anterior termination, so that there comes to be one vesicle 
above, one in front of, and. one below the anterior termination of 
the chorda. 

These vesicles are, as we shall hereafter see, the commencements 
of the future brain. 

In the walls of the ascending laminae dorsales, which bound 
the vesicles laterally, there are no quadrate thickenings like those 
developed on each side of the chorda in the 'vertebral region, 
while peculiar developments take place in their ventral laminae. 
For while the medullary groove is being arched over and con- 
verted into the great axial, neural canal, by the ascending laminae 
dorsales, another axial canal is being formed beneath the neural 
one by the descending lamina ventrales. This second axial canal 
is the rudimentary alimentary one. The ventral laminae, as they 
bend down to enclose the incipient pharynx, grow thinner and 
thinner at successive intervals, one behind the other, till a series 
of perforations, the visceral clefts, are formed, one after the other, 
each cleft leading from the exterior into the pharyngeal cavity. 
Four such visceral clefts appear on each side. The perforation 
proceeds from within outwards, the hypoblast being absorbed first, 
then the inner part of the mesoblast, and finally, the whole of the 
mesoblast, the hypoblast growing outwards along each advancing 
wall of each aperture, and ultimately becoming continuous with 
the epiblast. In front of each cleft the wall of the ventral lamina 
becomes more or less thickened, forming what are called the 
visceral arches (Fig. 152, \ 2 , 3 , *j — each such lateral series of arches 
being at first separate from their fellows of the opposite side, as 
are the ventral laminae themselves. Meantime another pair of 
vesicles — the cerebral vesicles — grow forwards (side by side) from 
that which was at first the most anterior vesicle ; and a pit formed 
beneath the outer anterior part of each cerebral vesicle lays the 
foundation of the future nasal organs (Fig. 152, no), while two 
other and more posterior invaginations on each side (one beneath 
what was the first vesicle and the other beside the hindmost) 
respectively lay the foundations of the eye and of the ear. The 
mouth is formed by a superficial depression — as will be subsequently 
more fully explained. On each side of the mouth the first visceral 
arch has meantime grown down and united distally with its fellow of 



336 



THE CAT. 



[CHAP. X. 




Fig 153. — Outline of the Head and Neck of an Embryo 
Pig, two-thirds of an inch in length, seen laterally 
Magnified seven diameters. 



the opposite side toform 
the lower jaw, while 
a process grows for- 
ward and upward from 
the more proximal 
part of each first 
visceral arch, such 
growth, termed the 
maxillary process (Fig. 
152, mps), laying the 
foundation of the up- 
per jaw. The two 
maxillary processes do 
not, however, join to- 
gether in front, but 
both join a median 
down growth, termed 
the naso-frontal process 
(Fig. 152, m). This 
last-named process de- 
scends from the front 
end of the floor of 
the incipient cranium, 
and has on each side 
of it one of the two 
depressions which are 
the incipient olfactory 
sacs. Its lower end 
forms the -middle of 
the front of the upper 
jaw, while the max- 
illary processes which 
unite with its distal 
end, on each side,form 
the sides of the upper 
jaw. The interval left 
on each side (above 
the junction of the 
naso-frontal and max- 
illary processes,) forms 
the nasal passage, and, 
in part, the lachrymal 

letters indicate the same parts in whichever of the above figures they occur, or in 




Fig. 154.— The Skull of the same Embryo (in its Incipient 
Stage of Development), seen from below. Magnified 
ten diameters (ventral aspect). 

The followin 
both figures :— 

c 1 to c 5 . The five divisions of the young brain. 

a. The eye. 

n. The nose. 

m. The mouth. 

tr. Cartilage of the trabecular 

ctr. Cornua trabeeularuni. 

pn. Pre-nasal cartilage. 

ppg. Pterygopalatine cartilage. 

mil. The mandibular arch, with Meckel's carti- 



lage. 
.te First visceral cleft, which becomes the tym- 
pano-Eustachian passage. 



ou. The auditory vesicle. 
hy. The cerato-hyoid arch. 
lr (1 to 4). The branchiabbars and clefts. 
thh. The thyro-hyoid. 
py. The pituitary fossa. 

ch. The notochord in the cranial basis, sur- 
rounded by the investing mass (iv). 
VII. Facial nerve. 

IX. Glossopharyngeal. 

X. Pneumogastric. 
XII. Hypo-glossal. 



chap, x.] THE DEVELOPMENT OF THE CAT. 337 

canal. The first visceral cleft persists on each side as the external 
auditory meatus, the tympanum and Eustachian tube. The other 
visceral clefts all successively close up and disappear. The primitive 
roof of the mouth is formed by the floor of the cranial cavity; 
subsequently a lateral growth from each maxillary process extends in- 
wards so as to form a partition across the upper part of the primitive 
buccal cavity, thus constituting the palate, and separating the hinder 
parts of the nasal passages from the mouth. The posterior nares 
open at first (before this growth of the palate) into quite the anterior 
part of the primitive buccal cavity. 

The cartilaginous basis* of the true future cranium is laid at 
the anterior end of the chorda dorsalis, which becomes surrounded 
by a solid, flattened mass of cartilage called the basi -cranial plate or 
parachordal cartilage, which, is the precursor of the basilar part of 
the occipital bone. 

Continuous with this on each side is a rounded portion of cartilage, 
which encloses the primitive ear (formed by a depression of the 
surface, as before mentioned) and is the precursor of the petrous 
part of the temporal bone (Fig. 154, an). The basi-cranial cartilage 
grows up on each side, and these lateral parts meet together above 
and enclose the foramen magnum with a cartilaginous ring. The 
basi-cranial plate, together with the enclosed chorda, stops short 
anteriorly at the hinder margin of what later becomes the sella 
turcica. 

From the front of the basi-cranial plate two cartilaginous rods, 
called the trabecule cranii (Figs. 153 and 154, tr), extend forwards. 
They at first diverge, but afterwards converge and meet, thus 
enclosing between them the place of the future pituitary fossa 
(Fig. 154, py). The trabecule at their anterior junction form a 
cartilaginous expansion called the ethmo-vomerine plate, which sends 
downwards three other plates to form the median and lateral 
ethmoids (thus embracing the two primitive olfactory sacs,) in- 
growths of the lateral ethmoids forming the future maxiHo-turbinals. 
Also two small cartilages appear, on each side of the cranial cavity, 
as forerunners of the ali- and orbito-sphenoids. 

The walls and roof of the skull are otherwise completed by 
membrane only, until the commencement of that membrane's 
ossification. 

There are certain other cartilages, however, which play an 
important part in forming certain parts of the bony skull, namely, 
the cartilages of the visceral arches. 

The first of these descending rods of cartilage, is connected above 
with the cartilaginous auolitory capsule, and is called " Meckel's 
cartilage " (Figs. 153 and 154, mn). What has the appearance of 
being merely an outgrowth forwards from this first descending rod 
(the maxillary process of the first visceral arch) lays the cartilaginous 
foundation of the bony upper jaw, including the pterygoid and 
palatine bones (pps), while the rest of Meckel's cartilage (beyond the 
point where such process is given off forwards) lays the cartilaginous 



338 TEE CAT. [chap. x. 

oundation for the lower jaw, and ends by uniting with its fellow of 
the opposite side. 

The next, or second cartilaginous rod (%), connected above, like 
the first, with the auditory capsule, descends in the second visceral 
arch, and lays the foundation of the anterior cornu and body of the 
os hyoides. 

The cartilage of the next visceral arch (Fig. 154, th) is the pre- 
cursor of the posterior cornu of the os hyoides. No noticeable 
permanent part of the skeleton is formed in the fourth visceral arch. 

§ 10. The process of ossification of the skull begins with the 
mandible, where one centre of ossification appears in each lateral 
moiety at an earlier period than in any other part of the skeleton. 
It is an ossification in the membrane investing Meckel's cartilage, 
and not in the cartilage itself. 

Immediately after the mandibular ossification, follows that of the 
maxillae and premaxillae. 

The premaxillae are ossifications in the cartilage of the naso- 
frontal process, while the maxillae are ossifications in the membrane 
investing the maxillary processes. The palatine and pterygoid 
bones arise as ossifications in the cartilage of the maxillary 
process. 

Fresh points of ossification also indicate the supra-occipital, the 
parietals and interparietals, the frontals, the squamosals, the vomer, 
the nasals, the lachrymals, and the malars, all these bones being 
ossified directly from membrane, and not through pre-existing 
cartilage ; but cartilaginous ossifications also indicate the future 
basi- and ex-occipitals, the ali-sphenoids, the basi- sphenoids, and the 
orbito-sphenoids, with the pre-sphenoid, as also the palatines and 
pterygoids, as above mentioned. Other ossifications arise successively 
and at various intervals. Thus, the median ethmoid and cribriform 
plate ossify late, as also do the bones of the os hyoides. The vomer 
is an ossification of the membrane investing laterally the lowest part 
of the ethmo- vomerine cartilage. 

The occipital bone for a time exists in four distinct pieces, the 
basi-, ex- and supra- occipitals. 

The frontal bones remain divided from one another by a con- 
tinuation forwards of the sagittal suture. 

The sphenoid bone consists at an early period of eight distinct 
and significant parts : the bulk of the body, or basi-sphenoid ; the 
front part of the body, or pre sphenoid ; the greater wings, or ali- 
sphenoids ; the lesser wings, or orbito-sphenoids ; and the true 
pterygoid bones. 

The temporal bone arises from many distinct centres, and consists 
for a time of several distinct bones. Amongst these bones are the 
squamosal (including the squamous part and zygomatic process), the 
tympanic parts, and the tympano-hyal. The bone which forms 
the inner and larger chamber of the tympanic cavity does not 
appear till a fortnight after birth. It sends in a process to form the 
septum, as does also the outer tympanic bone, so that the septum in 



chap, x.] THE DEVELOPMENT OF THE CAT. 339 

the adult really consists of two layers of bone which, have anchy- 
losed together. 

Besides these four elements, three other distinct ossifications arise 
in the primitive cartilaginous auditory capsule, spread and coalesce 
to form the petrous and mastoid portions of the temporal bone. 
They are distinguished by their various relations to different parts 
of the bony and membranous labyrinths. The first of these is called 
the pro-otic, and forms the upper rim of the fenestra ovalis, and 
invests the anterior vertical semicircular canal. It ultimately forms 
that part of the petrous bone visible inside the skull and part of the 
mastoid. The second ossification is the beginning of the opisthotic. 
It forms the lower rim of the fenestra ovalis, and entirely surrounds 
the fenestra rotunda. It constitutes the lower part of the petrous 
bone. The third ossification results in a bone called the epiotic y 
which invests the posterior vertical semicircular canal. It ultimately 
forms the mastoid process. 

The auditory ossicles are formed, in part at least, by ossifications 
of the proximal ends of the cartilages of the first and second visceral 
arches. 

That of the first arch, or Meckel's cartilage, long persists on the 
inner side of the mandibular ramus, but its upper end ossifies as the 
processus gracilis and body of the malleus. The proximal end of 
the second arch, which appears at one period to be bifurcated, has 
as ossifications of one of its upper ends, the tympano and stylo-hyals, 
while the other end becomes the body and long crus of the incus, 
the latter being its apex and summit. 

The stapes is of a different nature, being a small part of the 
cranial wall which has grown out, become separated, and secondarily 
connected with the upper part of the second arch. 

The lower end of this arch ossifies as the epi-, cerato- and basi-hyals- 

The os orbiculare is the uppermost end of that part, the lower 
portion of which is the thyro-hyal. 

The thyro-hyals are the solitary ossifications of the third viscera 
arch. 

Thus, in recapitulation, the skull as a whole may be said to arise 
as follows : — the cranial walls and floor behind, are formed from the 
parachordal and auditory capsular cartilages ; in front, by the trabe- 
cular, the ethmovomerine plate, alas and orbital cartilages ; above, 
from membrane. The visceral arches form the jaws and hyoid, in 
conjunction with downgrowths from the ethmovomerine plate. The 
trabecular extend forwards between the floor of the brain cavity and 
the roof of the pharynx, closely embracing the pituitary fossa, into 
which the roof of the primitive buccal cavity temporarily (see below, 
p. 343) projects. 

§ 11. The limbs of the embryo begin as two slight prominences on 
the surface of each lamina ventralis. They subsequently take the 
form of somewhat cylindrical processes, each with a flattened terminal 
expansion (Fig. 152). This expansion becomes divided at its distal 
end into five processes (the digits), the pre- axial one of which in 

z 2 



340 THE CAT. [chap. x. 

each, limb diverges from the others to a certain extent. The hallux, 
however, does not continue to develope. At first each limb is so 
placed that its dorsal surface is outwards, and thus the concavities 
of both the elbow and knee are directed inwards. As development 
proceeds, the two limbs are both rotated, but in opposite directions. 
The fore-limb becomes so rotated that the extensor surface is turned 
backwards, while the pelvic limb is rotated so that the correspond- 
ing surface is turned forwards. Thus, the elbow and knee come to 
be bent in opposite directions. The pelvic limb requires no further 
torsion, since the foot is now ready to assume the posture needful 
for locomotion. The bent arm, however, would have the back of 
the fore- paw turned downwards if no farther change took place — a 
posture manifestly inconsistent with the animal's mode of walking, 
which requires the palmar surface to be applied to the ground. 
This difficulty is obviated by a further torsion, but one which is 
confined to the forearm and paw. This further torsion consists in a 
change from the primitive condition of supination into that before 
described as pronation. With the exception of the clavicle, all the 
bones of the fore-limb are preformed in cartilage. 

In the scapula the coracoid process shows a separate centre of 
ossification, and two such appear in the acromion process. The 
supra-spinous part of the scapula ossifies as a separate plate of bone, 
and is quite distinct from the rest at birth. 

The humerus arises from one main ossification in the shaft, and 
two terminal epiphyses. The proximal epiphysis arises from three 
centres, one in the head and one in each tuberosity. The distal 
epiphysis arises from four centres, which respectively appear in the 
two condyles, the capitellum and the trochlea. Both the radius and 
the ulna ossify from one central ossification in the shaft, and two 
terminal epiphyses. 

Ossification of the carpus begins later than does that of the meta- 
carpus and digits ; only one centre of ossification is formed in each 
carpal, except the scapho-lunar, which has two. 

The first, or most pre-axial metacarpal (that of the pollex), has 
its epiphysis at its proximal end. The epiphysis of the other meta- 
carpals is placed at the distal end of each. All the phalanges 
without exception have their epiphyses at their distal ends (Fig. 60). 

The ossification of the lower limb begins soon after that of the 
upper, a bony nucleus appearing early in the shaft of the femur, and 
also in that of the tibia. Apart from the patella, all the bones of 
the pelvic limb ossify from cartilage. 

The os innominatum arises from three centres — those of the ilium, 
ischium and pubis — with certain epiphyses, the principal of which 
are one on the tuberosity of the ischium and another along the 
crest of the ilium. 

The femur (Fig. 6) has one epiphysis for its head, one for each 
trochanter and one for its distal end. 

The tibia and fibula have each one principal ossification — that of 
the shaft — and two terminal epiphyses. In the tibia the superior 



chap, x.] THE DEVELOPMENT OF THE CAT. 341 

epiphysis is the first to appear and the last to unite. In the fibula 
the superior epiphysis is both the last to appear and also to unite. 

The tarsals each ossify from one centre, as do the carpals, except 
the os calcis, which has also an epiphysis at the end of its tuberosity. 

The metatarsals and phalanges of the hind-foot (or pes) ossify in 
the same way as do the corresponding parts of the fore -foot (or 
maims), except that the hallux remains in a very rudimentary con- 
dition. The bony parts of the hind-paw ossify at about the same 
time as do those of the fore-paw. 

§ 12. The muscles of the trunk arise in what are called the 
"muscle-plates " of the primordial vertebrae, forming, as such plates 
do, the upper part of each dorsal segment. Hence are derived the 
erector spinae mass of muscles, the segments of which primitively 
correspond in number and position with the vertebrae themselves. 
The muscles of the abdominal wall are formed in the mesoblast of 
the somatopleure. The sub-vertebral muscles, such as the longus 
colli, &c, are formed in the mesoblast, which lies nearer the centre 
than the division between the somatopleure and splanchnopleure 
ever extends. The muscles of the limbs do not arise as protrusions 
of the body muscles outwards. They are directly formed in 
the mesoblast of the budding members themselves. 

§ 13. The alimentary canal is formed, as has been already 
intimated, by the splanchnopleure and hypoblast. It is at first in 
the form of an axially directed groove placed beneath the notochord, 
and opens downwards towards the yelk — and therefore is turned in 
the opposite direction to the medullary groove above it. The walls 
of the groove are, on each side and in front and behind, formed by 
mesoblast, everywhere lined by the hypoblast. This groove soon 
changes (by the descent and convergence of the splanchnopleure on 
both sides of it) into a canal. At each end (i.e., at the head and 
tail end) of this canal, the descending ventral laminae (which are there 
undifferentiated into somatopleure and splanchnopleure), close it in; 
so that, as has been already Said, the incipient alimentary canal at 
first ends blindly both in front and behind, though in its middle it 
remains open, communicating with the yelk or vitelline sac by 
means of the vitelline duct. When the communication is almost 
closed up, the vitelline sac takes the name of the umbilical vesicle, 
and on it ramify certain blood-vessels, which are, for a time, of 
great importance. 

The incipient alimentary canal is straight, cylindrical and attached 
to the underside of the vertebral column by a wide but thin layer of 
mesoblast. After a time the tube, towards the middle of the body, 
bends down away from the vertebral column, pulling out, as it were, 
the interposed layer of mesoblast into a thin vertically extended 
membrane, the future mesentery. Part of the tube on the anterior 
(cephalic) side of this loop or curve, dilates more and more and 
becomes the stomach ; the part on the posterior side of the loop be- 
comes the transverse colon. To the most prominent and middle part 
of the loop itself, the pedicle of the umbilical vesicle is attached. In 



342 



TEE CAT. 



[CHAP. X. 



subsequent development, the part of the loop pre-axial to this point 
of attachment, increases in length vastly more than does the part 
post-axial to it. The part in front (pre-axial) becomes the duode- 
num, jejunum, and the greater part of the ileum. The part behind 




Fig. 155.— Longitudinal Vertical Section through an Embryo, showing the incipient 
Intestine with the relations to it of the Lungs and Liver. 



d. Intestine. 

0. Mouth. 
a. Anus. 

1. Lungs. 
h. Liver. 

g. Mesentery. 
v. Auricle of heart, 
fc. Ventricle of heart. 
I). Arterial arches. 
t. Aorta. 



c. Yelk-sac. 

m. Duct leading from the intestine to the yelk- 
sac. 
u. Allantois. 
r. Stalk of allantois. 
n. Amnion. 
w. Cavity of amnion, 
s. Outer layer of primitive amniotic fold, which 

is separating off to coalesce with the inside 

of the primitive chorion. 



(post-axial to) the attachment of the umbilical vesicle, becomes the 
rest of the ileum and the colon. Thus that proximity of the transverse 
colon to the stomach and duodenum which we have seen in the 
adult condition, is initiated at first ; the long intervening tract 
being formed by the outgrowth and coiling of the primitive loop, the 
distal ends of which (stomach and transverse colon) preserve very 
nearly their primitive relations. The distinction between the large 
and small intestine is first indicated by a small prominence, the 
future caecum, which appears a little post- axial to the attachment of 
the vitelline duct of the umbilical vesicle. The large intestine is, at 
first, of less capacity than the small. 

The formation of what are ultimately the two ends of the 
alimentary canal, namely the mouth and anus, has already been 
incidentally referred to. The primitive pre-axial end of the alimen- 
tary canal reaches beneath the skull, where it ends blindly below 
the pituitary space and forms the oesophagus and pharynx. 

The anterior end of the canal is at first closed by the lamina 
ventralis, which descends in front of it as a single plate, not divided 
into an outer somatopleure and an inner splanchnopleure. In the 



chap, x.] THE DEVELOPMENT OF TEE CAT. 343 

external surface of the pre-axial end of the embryo, the mouth 
appears as a depression on the surface of the front end of the head. 
This depression is hounded above by the naso-frontal process and 
below by the first visceral arch, and the tongue arises in the floor of 
the chamber thus formed. This primitive buccal cavity extends 
back beneath the cerebral vesicles till it meets the blind end of the 
front of the pharynx, into which it soon opens by a process of 
absorption of the intervening partition formed by the just mentioned 
lamina ventralis, part of which partition persists as the velum 
palati. An upgrowth from the buccal cavity, the pituitary body, 
meets a downgrowth (between the trabecular) of the brain — the 
infundibulum. It is thus these parts are formed. Afterwards the 
pituitary body becomes cut off from the buccal cavity and adheres 
to the infundibulum. 

The anus is formed in an analogous manner at the post-axial 
end of the embryo. Here at first the intestinal groove is continuous 
with the medullary groove round the hind end of the chorda 
dorsalis, but the ventral lamina descends behind, as a single plate 
not divided into an outer somatopleure and an inner splanchnopleure, 
and closes in the hinder end ot the alimentary tube. The hinder- 
most part of this primitive tube is called the cloaca. Beneath the 
posterior end of the chorda a depression of the epiblast appears ; 
this deepens, and the mesoblast of the ventral lamina is absorbed, 
a perforation being effected and the rectum and anus thus formed. It 
is from the ventral wall of the cloaca that the allantoic sac before 
described grows out, but it grows out beyond the point where the 
ventral lamina begins to be differentiated into somatopleure and 
splanchnopleure. It grows out therefore from the latter into the 
interspace dividing those lamellar subdivisions of the mesoblast. 

The teeth are developed each by a double process. In the place 
for each tooth that is to be, a depression takes place in the mucous 
membrane of the gum, the deepest layer of the epithelium thicken- 
ing and extending into such depression. The sac of epithelium 
thus formed widens at its deepest part, while simultaneously a papilla 
of the mucous membrane rises up from below and pushes itself into 
the deep surface of the widened part of such epithelial sac. The 
mucous papilla ultimately becomes the mass of the future tooth, 
while the deepest surface of the epithelial inflection (into which the 
ascending papilla has protruded) becomes the enamel of the tooth, 
on which account it is called the " enamel organ''' Thus each tooth 
arises from tw T o distinct sources. In the process described, the neck 
of the epithelial depression becomes exceedingly attenuated, while 
what is called a " dental sac" forms itself about the developing tooth 
by direct transformation of the mucous membrane, into an outer 
layer of fibrous tissue with a vascular layer within. The contained 
papilla then assumes the shape of the crown of the future tooth, 
and soon begins to calcify, thin caps of dentine being formed on 
the milk teeth within the gum, at an early period during gestation, 
each cap thickening by degrees as it extends its margins. As soon 



5'44 THE CAT. [chap. x. 

as the crown of the tooth is completed its base becomes constricted, 
and then, as it grows, the papilla becomes narrower and so the fang 
is formed, its soft substance becoming smaller and smaller through 
the progress of calcification around it, till nothing but a minute 
central pulp cavity is left, through which the vessels and nerves 
pass. If the tooth be a molar, a separate cap of dentine is formed 
at first for each cusp, while when the crown has been formed, the 
development of the papilla becomes modified by the cessation of its 
growth in certain parts (with corresponding ingrowths from the 
alveolus), so that it becomes subdivided into as many parts as the 
tooth is to have roots. The soft tissue left is the foundation of the 
future roots, the pulp of the tooth now adhering only by them 
instead of by one undivided soft body, as is the case where there is 
to be but one root. 

From the epithelial sac of each growing first (or milk) tooth, a 
little diverticulum is given off, containing a continuation of the 
primitively inflected epithelium, and against this, another small 
papilla rises and imbeds itself, and thus the foundation of each 
second or permanent tooth is laid. The relations of the milk and 
permanent teeth have been already given in the second chapter. 

As the teeth are formed, so also are the bony walls of the alveoli 
which grow up and come to surround and embrace them. 

The formation of the dentine of the teeth takes place by 
gradual transformation of the surface of the dental papilla (consist- 
ing of round nucleated cells in a clear matrix) in such a way as to 
leave the dental tubuli open, as already described. 

The enamel is formed by more complete transformation into 
mineral substance of the epithelial enamel organ, while the cement 
is formed by the ossification of the connective tissue immediately 
surrounding the dental papilla, and leaving not only tubuli, but as 
we have already seen, corpuscles similar in form and nature to the 
corpuscles of true osseous tissue. 

The liver arises as two diverticula given off from each side of 
the alimentary canal, immediately behind the stomach (Fig. 155, h), 
each diverticulum consisting of both mesoblast and hypoblast. The 
former thickens greatly, and becomes very vascular, while canals 
from the two primitive diverticula extend and ramify within the 
cylinders of anastomosing cells which it builds up. The growth of 
this organ is extremely rapid. At first the liver is almost quite 
symmetrical in form, its right and left lobes being nearly equal. 
The gall-bladder arises as a special diverticulum of both hypoblast 
and mesoblast. 

The pancreas appears as a bud from the left side of the duo- 
denum, where both hypoblast and mesoblast are thickened ; canals 
lined with the former ultimately being developed within the latter. 

The salivary glands arise in a similar manner at the anterior 
end of the elementary tube. They differ from the pancreas, however, 
inasmuch as their cavities are lined with epiblast, since this it is 
which forms the lining of the buccal invagination. 



chap, x.] THE DEVELOPMENT OF THE CAT. 345 

The peritoneum, so complicated in the adult, arises as simply the 
lining membrane of the adjacent surfaces of the two diverging plates 
(somatopleure and splanchnopleure), into which each ventral lamina 
splits. Therefore, for a time, the primitive peritoneal cavities of the 
two sides are continuous with each other, not on the ventral side of 
the embryo only, but, as before pointed out, over its back, between 
those doubled folds of somatopleure which ascend on all sides to form 
the amnion (Fig. 148, 2 ~ 5 ). 

As the somatopleures descend and gradually embrace the ali- 
mentary canal — formed by the splanchnopleures — they enclose 
more and more the peritoneal cavity, and when they come to meet 
together below, they do so completely (Fig. 147, C, D). 

It has already been seen that the divergence of the middle part 
of the alimentary tube from the vertebral column produces an in- 
cipient mesentery. By a continuation of this process the alimentary 
canal comes to be slung, from the skeletal axis, in a mesenteric 
peritoneal fold. With the increasing complexity of contortion into 
which the alimentary canal is thrown by its great increase in length, 
a corresponding increase of complexity is induced in the mesenteric 
folds by which it is slung. A pouch of it, having of course four 
walls, becomes protruded ventrally between the stomach and trans- 
verse colon, and so forms the omentum. 

§ 14. The blood makes its first appearance in the interior of the 
primitive blood-vessels, as already described. Both blood and 
blood-vessels begin to appear first in that layer of the blastoderm 
which is immediately adjacent to the embryo. 

Certain of the primitive mesoblastic cells of the embryo become 
masses of corpuscles in fluid, enveloped by more solid nucleated pro- 
toplasm — the primitive walls of the vessels. These arise, as before 
explained,* from the junction of radiating processes of adjacent cells, 
the cavities of which open one into another. Blood-vessels are at 
first confined in the embryo's body to the splanchnopleure. 

The heart arises as an elongated cavity in the splanchnopleure 
of the anterior end of the embryo. It consists at first merely of 
nucleated cells, and its rythmical contractions begin while in this 
incipient, merely cellular condition, and before the muscular fibres, 
which subsequently arise, are developed. Its first form is that of 
an elongated vesicle, or tube, into the posterior end of which two 
veins open, while a large artery proceeds from its front end. It 
increases in size and thickness, and bends over in a crescentic loop, 
projecting downwards and towards the right. At the same time two 
slight constrictions divide it more or less into three successive 
portions. The hindermost of these (that into which the two veins 
open) becomes the future auricles.' The next portion becomes the 
ventricles, while the most anterior segment, from which the great 
artery proceeds, is called the bulbus arteriosus. As the heart be- 
comes more and more bent, the auricular portion approaches the 

* P. 331. 



346 THE CAT [chap. x 

ventricular portion, which latter comes to lie transversely. Mean- 
time a septum grows up, dividing the ventricular part into a right 
and a left chamber. The septum extends on into the bulbus, which 
becomes divided into two channels, those of the aorta and of the 
pulmonary artery respectively. As soon as the ventricular septum 
is complete, another septum begins to divide the auricular portion 
into a right and left chamber, but this septum remains incomplete 
even at birth, when an aperture, the foramen ovale, still remains, and 
allows the blood to pass directly from the right to the left auricle 
without passing through, the lungs. It is the existence of this 
perforation in the new-born kitten * which renders the drowning of 
it so long a process. 

The more important arteries arise as follows. The aortic bulb 
gives off at first two arteries which run forwards till they reach the first 
visceral arch, inside which they pass upwards to beneath the spine, 
where they unite together to form the incipient dorsal aorta. As 
the length between the most anterior part of these primitive aortic 
arches and the heart, lengthens (from the growth of the embryo), 
other arches successively arise from the forwardly extending bulb, 
and ascend to the backwardly extending root of the dorsal aorta, 
forming, as it were, a succession of short cuts on each side to the 
dorsal aorta (Fig. 156, l 2 3 *). Four vessels thus arise on each 
side behind the first, and respectively ascend inside successive visceral 
arches to the aorta. There are thus five such ascending arches 
developed on each side, though only three exist at the same time, 
the earlier and more anterior disappearing as the later ones arise. 

Ultimately the fourth arch of the left side persists, grows, and 
becomes the arch of the adult aorta. That of the right side becomes 
the innominate and right subclavian and carotid arteries. The more 
anteriorly situated arches become transformed into branches of the 
carotids. The fifth arch disappears on the right side altogether, but 
that of the left becomes the pulmonary artery, a communication 
between it and the great aorta persisting till a little after birth as 
the ductus arteriosus (Fig. 157, da), a relic of which is seen in the 
fibrous cord which connects together these arteries in the adult. 

The descending aorta at first gives off on each siae a large omphalo- 
meseraic artery (Fig. 156, onia), which goes to the vitelline sac, or 
umbilical vesicle ; but these branches dwindle as the aorta comes to 
give origin to two other considerable and more posteriorly situated 
arteries (ua) called umbilical (the future hypogastric ones), which 
proceed into the allantois and placenta. From each umbilical 
artery a comparatively small branch (I/a), the future iliac artery, is 
given off, and goes to the incipient pelvic limb. 

In the process of their development the more notable veins 
undergo remarkable changes. The first important veins to appear 
are two which pass upwards from the umbilical vesicle to the heart, 
and are called the right and left omphalo-meseraic veins (Fig. 156, 

* I have found this foramen still open a week after birth. 



CHAP. X.] 



THE DEVELOPMENT OF THE CAT. 



347 



omv), and which, as it were, lay the foundation of the future portal 
and hepatic veins. Before entering the incipient auricular end of the 
primitive heart, these omphalo-meseraic veins first unite into a common 
trunk and then dilate into a venous chamber, which bears the name 
of sinus venosus (Fig. 156, S), and opens directly into the heart. 




Tig. 156.— Diagram of Fostal Arteries and 
Veins. Very early condition. The 
Arteries and Veins of one side only 
are represented to avoid confusion. 

5. Sinus venosus. 

A. Auricle. 
V. Ventricle. 

B. Bulbus arteriosus. 
L. Liver. 

1, 2, 3, 4. Aortic arches. 

a. Dorsal aorta. 

oma. Omphalo-meseraic artery to umbili3> 

vesicle. 
iia. Umbilical artery (to allantois). 
ila. Iliac artery to incipient hind-limb, 
ere. Caudal artery. 
omv. Omphalo-meseraic vein. 
uv. Umbilical vein. 
dv. Ductus venosus. 
hv. Hepatic vein. 
ilv. Iliac vein. 
vci. Inferior vena cava. 
fc. Posterior cardinal vein. 
ac. Anterior cardinal vein. 
dc. Ductus Cuvieri. 



Fig. 157.— Diagram of the Foztal Circula- 
tion THROUGH THE HEART AND AORTA. 

Condition of Heart and Great Vessels 
at Birth. 

RA. Right auricle. 

LA . Left auricle. 

R V. Right ventricle. 

LV. Left ventricle. 

A 1 . Great aorta. 

A 2 . Second aortic arch (afterwards pulmonary 
artery). 

pa, pa. Incipient branches to lungs 

da. Ductus arteriosus, which at first places the 
two aortic arches in direct communication. 
The arrows indicate the course of the blood, 
one going directly from the right to the 
left auricle through the foramen ovale of 
the as yet incomplete inter-auricular 
septum. 



Soon two elongated venous trunks make their appearance beneath, and 
parallel to, the primitive vertebral column (ac an&pc), each such 
vein sending down a branch, called a ductus Cuvieri (dc), to the 
sinus venosus. That part of each of these two trunks which runs 
backwards from the head end of the embryo to its ductus Cuvieri, 
is called an anterior cardinal vein. That part of each of these 
trunks which runs forwards from the hinder part of the embryo to 
the ductus Cuvieri of such trunk is called a posterior cardinal vein, 
which ultimatelv become the azvgos vein. Before the commence- 



348 TEE CAT. [chap. x. 

merit of the placental circulation, the only important veins besides 
the cardinal ones are the omphalo-meseraic veins ; but with the 
beginning of the placental circulation two veins, called the right and 
left umbilical veins (uv), come from the placenta, pass up the allantois 
and join the omphalo-meseraic veins at their entrance into the 
liver. The right ornphalo-meseraic vein and the right umbilical 
vein soon disappear altogether. The left omphalo-meseraic vein 
sinks by degrees into comparative insignificance, but is joined by 
the now more important mesenteric veins. Of the vessel thus formed, 
that part which is on the heart side of the liver, ultimately becomes 
the vessel connecting the hepatic veins with the heart. The left 
(now the only) umbilical vein, joined by veins from the anterior 
abdominal walls and other parts, unites with what was the common 
omphalo-meseraic trunk, now become the portal vein, and also 
sends out branches (portal veins) into the growing liver, while much 
of the blood it brings is conveyed on by an undivided vein, called 
the ductus venosus (Fig. 156, dv), directly to the sinus venosus. 
Meantime other veins — the hepatic veins (ho) — form in the substance 
of the liver and open close beside the opening of the ductus venosus 
into the sinus venosus. Thus what was originally the combined 
trunks of the omphalo-meseraic and umbilical veins persists till birth 
as the ductus venosus, while diversely directed branching veins 
(forming two systems, the portal and the hepatic), are developed in 
connection with it — the portal system of veins diverging into the 
liver from near the proximal end of the ductus venosus, while the 
hepatic veins converge towards the vicinity of the distal end of the 
ductus venosus. 

Meanwhile, concomitantly with the incipient development of the 
pelvic limbs, there arises the great system of the vena cava inferior 
(vet). This is formed by the junction of the veins of the legs and 
pelvic viscera (the incipient external and internal iliac veins) into a 
median trunk, which receives accessions from the kidneys (renal 
veins), and runs on beneath the great dorsal aorta to the heart, 
where, intruding upon the junction of the hepatic veins and sinus 
venosus, it ultimately absorbs, as it were, the latter chamber alto- 
gether, and thus the hepatic veins come in the adult to open into the 
vena cava inferior. 

During this period, the right ductus Cuvieri becomes attached to 
the developing right auricular part of the heart, and while the 
anterior cardinal veins become large and important, as the jugular 
and subclavian veins, the posterior cardinal veins become relatively 
reduced into the right and left vena azygos. Then a transverse 
communicating branch, which connects the two jugular veins, 
rapidly enlarges, while the left ductus Cuvieri diminishes and dis- 
appears. This transverse branch becomes the left innominate 
vein, and thus the right ductus Cuvieri (having now the right 
jugular and subclavian veins brought into connexion with it) be- 
comes transformed into the vena cava superior. The right azygos 
vein (the old right posterior cardinal vein) opens at last, as at first, 



chap, x.] THE DEVELOPMENT OF THE CAT. 349 

into what was the right d actus Cuvieri and what is ultimately the 
vena cava superior. The left azygos veins (the old left cardinal 
vein) open.? at last, as at first, into what was the right ductus 
Cuvieri, and what is ultimately that part of the superior intercostal 
vein which is nearest to the left innominate vein. 

After birth and the cessation of the placental circulation, the 
ductus venosus diminishes and becomes obliterated, save as that fibrous 
cord, the round ligament which traverses the liver. The umbilical 
vein also disappears, save as that part of the round ligament which 
extends from the umbilicus to the liver. Thenceforth all the blood 
returning from the stomach and intestines is compelled to circulate 
through the portal and hepatic veins on its way to the heart. 

Those parts of the umbilical arteries which are within the body — 
the hyogastric arteries — similarly abort where they intervene be- 
tween the bladder and the umbilicus, becoming merely two fibrous 
cords. Those parts which intervene between internal iliacs and the 
side of the bladder, persist as the superior vesical arteries. 

The development of the lymphatic system resembles more or 
less that of the blood-vascular system. The small lymphatics 
originate by the junction of nucleated cells, and they spread and 
increase through the development of peculiar cells, which branch 
out and join fine processes given off from the lymphatics formed 
earlier. The hjmphatic glands appear to be developed from clusters 
and aggregations of lymphatic vessels from which diverticula grow 
out. The hjmphatic corpuscles probably originate from subdivision of 
cells contained within the early formed lymphatic vessels and glands, 
also in the spleen and perhaps in the thyroid and thymus glands. 

The fluid lymph may be regarded, like the fluid blood, as the 
blastema of a tissue of which the white corpuscles represent the 
nucleated cells. 

§ 15. The lungs are at their origin small outgrowths from the 
alimentary canal (Fig. 155, /). This canal, at a point immediately 
behind the heart, becomes laterally constricted by two lateral in- 
foldings of its walls, which divide it into a narrower upper, and a 
broader lower (or ventral) channel, while the lower channel tends 
to be subdivided by a median longitudinal upgrowth from its floor. 
This process continuing, three tubes come to be formed, whereof the 
dorsal one is the future oesophagus, while the two ventral ones 
become the two lungs, which thus arise as two diverticula, lined 
with hypoblast, from the ventral aspect of the oesophagus. These 
little sacs elongate by degrees, and ultimately come to hang by a 
single and common supporting tube, the future trachea. Ramifica-. 
tions of the primitive cavity into the mesoblastic tissue surrounding 
it, form the bronchial tubes, with their branches. 

In contrast with the liver, the lungs of the foetus are exceedingly 
small, but as soon as the first inspiration has taken place, they 
rapidly increase in size and weight, while their consistency changes 
from that of a granular, compact, heavy substance, to a light and 
spongy texture. 



350 THE CAT. [chap. x. 

The larynx first becomes visible by the rudiments of the cartilages 
which appear about the primitive glottis, the arytenoids seeming to 
be the first, and the epiglottis the last to appear. 

The spleen is formed entirely from the mesoblast, a thickening 
of which appears on the left side of" the stomach, near the pancreas. 
No prolongation from the alimentary canal ever enters it, or even 
appears in connexion with it. 

The thyroid body arises as a small diverticulum, lined with hypo- 
blast, from the anterior wall of the pharynx, and consists of isolated 
vesicles, within which are rounded cells, the vesicles multiplying by 
constriction and division — or by budding out and separation — of 
such protruded parts. It is larger relatively in the foetal and young 
condition than in adult age. 

The thymus gland is a body which makes its appearance as 
a tube with granular contents, surrounded by tissue into which 
small vesicles bud forth, laterally, from it — which vesicles themselves 
again branch. The thymus is relatively larger at birth than subse- 
quently but it still remains of large size, even at maturity. 

§ 16, The first urinary organs which make their appearand 
in the embryo are not the kidneys, but certain temporary urinary 
glands called the Wolffian bodies (Fig. 151), which early attain 
a large relative size. Afterwards their place is taken by the true 
kidneys. The Wolffian bodies entirely losing all secreting power, and 
more or less aborting, become (in one or the other sex) either im- 
portant or merely functionless appendages of the generative organs. 

The Wolffian bodies make their appearance in the embryo (at a 
time when the intestinal canal still communicates widely with the 
umbilical vesicle) as a slight ridge on each side of the primitive 
mesentery, and each body grows to 'be a reddish oblong mass beside 
the vertebral column, reaching from the heart to the hinder end of 
the abdomen. It consists of a series of tubes all opening into a 
duct which runs along the outer border of the Wolffian body. Each 
tube is somewhat convoluted and dilated at its blind end as a Mal- 
pighian body, into which a vascular glomerulus enters, just as in 
the true kidney — the Wolffian bodies being very vascular. The 
ducts of the two Wolffian bodies open near together into the root 
of the allantois. 

The first parts to be developed of the Wolffian bodies are their 
ducts, which appear to arise from a series of invaginations (from the 
primitive pleuro-peritoneal cavity) into that part of the mesoblast 
which lies in the angle between the diverging somatopleure and 
splanchno-pleure. The blind ends of these invaginations grow out 
laterally and coalesce, so as to form a rod traversing the mesoblast 
antero-posteriorly, while the invaginations, which originally led 
from the peritoneal sac, close up and disappear. The central part 
of the rod developes a cavity, and thus the tube of the Wolffian 
ducts comes to be formed. After this, diverticula bud off laterally 
from this duct, and so the tubes which end in the Malpighian 
bodies come to be formed. 



chap, x.] THE DEVELOPMENT OF THE CAT. 351 

While the Wolffian bodies are forming, another, single, invagina- 
tion is formed on its inner side, and this closes over, extends, and 
becomes a tube called the Mullerian duct. The two Mullerian 
ducts, which end blindly at their anterior end, extend backwards, 
meet and coalesce where they open (side by side and between the 
two Wolffian ducts) into the proximal part or root of the ailantois. 

The allantois itself, as has already been said, grows forth as a 
membranous sac from the hinder end of the ventral aspect of the 
primitive alimentary canal, and extends out between the somato- 
pleure and splanchnopleure to the inner surface of the chorion in 
the umbilical cord. 

As the visceral plates of the somatopleure close round the belly of 
the embryo, they come finally to embrace the umbilical cord where 
it quits the body. 

The part of the ailantois which is within the abdominal cavity, 
becomes differentiated into what are ultimately (1) the proximal part of 
the urethra, (2) the bladder and (3) the urachus : the urachus being that 
part of the ailantois intervening between the bladder and the umbilicus, 
or navel. The cavity of the urachus becomes narrower and narrower 
till it closes, and so this part becomes transformed into a ligament, 
with traces, perhaps, of its primitive cavity. The proximal part of 
the ailantois opens at first into the hinder end of the primitive 
alimentary cavity, but by degrees a partition (the future perineum) 
grows forwards horizontally, and divides the dorsal alimentary 
chamber, or rectum, from the ventral urogenital sinus, into which 
latter (the commencing proximal part of the urethra) the Wolffian 
and Mullerian ducts open (Fig. 158, A). 

The kidneys begin to appear as two oval dark-coloured bodies, 
each placed behind and above the very much larger Wolffian 
body of the same side. Nevertheless, each kidney is at first larger, 
compared with the bulk of the whole body, than in the adult. 

The kidneys themselves arise subsequent!)' to the development of 
their ducts, the ureters. These latter seem each to be formed from 
a dilatation of part of the Wolffian duct, which becomes constricted, 
and so the ureter arises as a separated-off diverticulum of such duct. 
This diverticulum, however, grows downwards and backwards, and 
opens, not into the urogenital sinus, but into the bladder (Fig. 158, A, 
b) which is separated from that sinus by a constriction. 

From the anterior end of each newly formed ureter diverticula 
grow forth into the mesoblast, and these diverticula lengthen, become 
greatly contorted, and end in true renal Malpighian corpuscles. It 
may be, however, as some contend, that the various parts arise 
separately in the formative tissue, each part at first being solid, but 
subsequently acquiring a cavity, and all ultimately uniting together. 

The supra -renal capsules arise quite independently of the 
kidneys. For a time they are much larger than the last named 
organs. They appear to originate as a single mass in front of the 
kidneys, subsequently becoming divided into two lateral organs. 

The testes appear after the Wolffian bodies, but before the 



352 TEE CAT. [chap. x. 

kidneys, as two small whitish oval masses of tissue, placed one on 
the inner side of each Wolffian hody, and arising as buds from the 
mesoblast, between the diverging somatopleure and splanchnopleure. 
Soon the cells of which they are composed become divided by septa 
of connective tissue, and the cells themselves grow into the tubuli 
seminiferi. Meanwhile, the tubes of the Wolffian body become 
approximated to, and ultimately united with, the testis, and form 
the rasa eflvrentia and coni vasculosi of the epididymis, the duct of 
the Wolffian body becoming the vas -deferens, some of its detached 
tubes forming the vas aberrans and Organ of Giraldes.* The testes 
ultimately descend from the abdominal cavity into the scrotum, 
which is formed by the median junction of two folds of skin, which 
grow from the sides of the external opening of the urogenital sinus. 

The penis first appears as a small recurved process projecting 
from the front margin of the urogenital opening (Fig. 158, A, rp), 
consisting of what are to be the corpora cavernosa, with a portion 
of corpus spongiosum at its distal end and extending down the 
grooved ventral, or posterior, surface of the developing organ. The 
lateral margins of this groove grow over and close, so converting the 
groove into a canal — the spongy portion of the urethra. This canal 
then opens posteriorly into the front end. of the urogenital sinus, 
which still opens externally at the root of the penis, though 
separated from the anal aperture by a transverse partition, the 
incipient perineum. By degrees this inferior opening of the uro- 
genital sinus grows over and closes, and thus the spongy urethra 
comes to form one continuous tube with the urethra as it quits the 
bladder, while the posterior end of the ventral surface of the penis 
becomes continuous with the medianly coalesced lateral folds which 
have formed the scrotum and invested the place where was the external 
opening of the urogenital sinus at the root of the developing penis. 

The ova"ry arises just as does the testis, and is at first indistin- 
guishable from it. Soon, however, it comes to differ somewhat in 
shape, and ova and Graafian vesicles arise from the very first within 
it. It does not form the same kind of adhesion to the Wolffian 
body as do the testes, but its stroma is formed by outgrowth of 
tissue into it from the Wolffian body. A fibrous cord, the round 
ligament, comes to connect the ovary with the pubis through the in- 
guinal ring, but the ovary never passes outside the abdominal cavity, 
though it descends a little from its primitive position. It becomes 
wrapped round by the fold of peritoneum, the broad ligament, which 
is reflected on each side from the uterus, so that no discharge of its 
contents can take place without rupture of its peritoneal investment. 
The vagina and u'erus arise as the partially conjoined hinder 
ends of the two Mullerian ducts, which open into the dorsal wall of 
the urogenital sinus (Fig. 158, B). The simple tube comes by 
degrees to alter in size and structure in different regions, its deeper 
portion becoming very muscular (as the uterus) and separated from 
the hinder part, the vagina, by a constriction forming the os uteri 

* See ante, p. 244. 



chap, x.] TEE DEVELOPMENT OF THE CAT. 

Pi 



353 




y9 



Fig. 15S. — Diagram of the Development op Generative Organs. The Body is supposed to 
be cut through vertically, and the urinary and generative organs of the 
Left Side to be viewed Laterally. 



A. The earliest or neutral condition, the sexual 

gland ($g) being as yet undifferentiated into 
either ovary or testis, and the Wolffian 
body (u>) and duct (wd), and the Mullerian 
duct (m), all co-existing with the permanent 
kidney (k) and ureter [uf, the papilla (rp) on 
the ventral side of the opening of the 
urethra (uh) being rudimentary. 

B. Here the neutral state is changing into the 

complete female condition. The sexual 
gland [sgo) has become an ovary. The 
"Wolffian body and duct (w and wd) have 
almost aborted. The remnant of the 
Wolffian body (w) has become the par- 
ovarium and Gaertner's duct. The Mul- 
lerian duct (m) has expanded and opened at 
its free end, and become a Fallopian tube, 
the lower end of which has coalesced with 
its fellow of the opposite side to form the 
vagina (v) and uterus {us). The opening 
ot the cornu of the right side is seen at oc. 



C. Here the neutral state is changing into the 
complete male condition. The sexual 
gland (sgt) has become a testis, and has 
travelled backwards and downwards into 
the scrotum (s)— its original position being 
indicated by dotted lines. The Mullerian 
duct (m) is reduced to a rudiment, the pros- 
tate has developed (pg), and the rudimentary 
papilla has become a relatively large organ 
(p), which is represented as truncated. 

a. Anal aperture. al. Allantois. b. Bladder. 

c. Clitoris. k. Kidney. m. Muller's duct. 

oc. Opening of right uterine cornu into uterus. 

pg. Prostate gland. 

rp. Rudimentary papilla, which becomes the 
penis in the male. 

s. Scrotum. 

sg. Undifferentiated sexual gland. 

sgo. Ovary. sgt. Testis. uh. Urethra. 

us. Uterus. ut. Ureter. v. Vagina. 

w. Wolffian body. wd. Wolffian duct 

A A 



354 



THE CAT. 



£CHAP. X. 



(Fig. 158, B). The two upper ends of the Mullerian ducts, above 
where they begin to form the uterine cornua, open at their deep 
ends, as already described, thus becoming the Fallopian tubes, 
which lead from the peritoneal cavity into the uterus. 

The fundamental similarities of the parts in the two sexes may 
be expressed as follows (Fig. 158, A, B, C) : the primitively formed 
"Wolffian body becomes in the male the vasa efferentia and coni 
vasculosi, otherwise it vanishes, save that the vas aberrans and 
hydatid of Morgagni, with the organ of Giraldes,* may be its more 
or less persistent relics. In the female both the Wolffian body and 
its duct practically disappear, the parovarium and Gaertner's duct 
being persistent remnants of them. In the male the Wolffian duct 
becomes the vas deferens. The Mullerian ducts, on the contrary, 
entirely disappear, except that the relics of their conjoined ends 
persist as the utricle or sinus pocularis ; while in the female, the 
Mullerian ducts become the oviducts, the uterus and the vagina. 
Thus the utricle is the minute male uterus. The small body formed 
on the front margin cf the cloaca becomes in the male the penis, 
the clitoris in the female. The groove which traverses it below and 
behind, closes in, in the male, to form the spongy urethra ; in the 
female it remains open. The folds of integument which lie on each 
side of the urogenital aperture, persist as such folds in the female, 
but, in the male, unite ventrally in the middle line to form the 
scrotum. The glands of Bertholin correspond with those of Cowper, 
but the prostate of the male has no, as yet discovered, analogue in 
the female. 

The development of the spermatozoa has been already described, 
together with the description of the testis, t Ova arise simply as 
epithelial cells, such as those which invest the incipient ovary, and 
generally line the peritoneal cavity. They also arise as (and from 
amongst) epithelial cells more deeply placed in the ovary ; but it is 
not certain whether such deeper cells arise inside quasi-glandular 
tubes formed of inflected superficial epithelium, or whether they are 
deep-seated because the connective tissue stroma of the ovary has 
grown outwards and enclosed them.]: The ordinary sized germ- 
epithelial cells are about T — - of an inch in diameter. The sub- 
stance of the ovary by which these cells become enclosed, is an 
•outgrowth from the Wolffian body. 

The epithelial cells become thus enclosed in groups or " nests," 
and some of them, enlarging in size and acquiring much clear 
protoplasm around their nucleus, become what are called primitive 
• or primordial ova, which average about -oW °f an i QCn i n diameter. 
Other adjacent epithelial cells divide and multiply, and form a 



* See oMe, pp. 244 and 250. 

+ See ante, p. 245. 

% As is the opinion of Mr. F. Balfour. 
See Quarterly Journal of Microscopic 
Science, October, 1878, p. 418, and 
Embryology, vol. i., p. 47. See also a 



paper by Dr. Foulis, in the Trans, of 
the Roy. Soc. of Edinb. , vol. xxvii., 
p. 345, and another by Mr. E. A. 
Schafer, on the Pro. Eoy. Soc, 1880, 
p. 245. 



chap, x.] THE DEVELOPMENT OF THE CAT. 



355 



cellular investment, or follicle, around the primordial ova, and 
ultimately grow into the tunica granulosa within the Graafian 
vesicle. Sometimes two or more of the ova-forming epithelial cells 
of a nest, will coalesce and form a large protoplasmic mass with two 
or more nuclei, and thus a cell may arise and then he nourished by 
appropriating the substance of other cells. An enlarged epithelial 




Fig. 159.— Portion of the Ovary of a Kitten about Three Weeks old, showing the Germ- 
epithelium and Primordial Ova. with large Egg-nests more or less sur- 
rounded by Stroma (Foulis). 



a. Primordial ova. 

b. Smaller cells, resulting from the fission of larger 

epithelial cells, and beginning to form the 
membrana granulosa. 



c. Large clusters of germ epithelial cells, 

large egg-nests. 

d. Large germ epithelial cells. 

e. Stroma of ovary. 

/. Germ epithelial cells. 



cell, or primordial ovum, when it has become enclosed in a follicle, 
becomes a " permanent ovum." The protoplasm, or vitellus, accu- 
mulates about the nucleus or germinal vesicle, which developes a 
nucleolus, or spot, while the zona pellucid a forms either just within or 
externally to a delicate membrane investing the vitellus. The ovum, 
with its epithelial lining and external investment of fibrous vascular 
stroma, is a " Graafian follicle." At first the ovum itself is closely 
embraced by the follicle. Afterwards the follicle greatly enlarges, 
and its contents separate into (1) the cells of the membrana granulosa, 
lining the vesicle and enclosing (2) a fluid, (3) the ovum, and (4) an 
aggregation of cells — the discus proligerus — which remains adherent 
around the ovum. The ovary at first contains thousands of incipient 
ova, but the great majority disappear as development proceeds. When 
the kitten is but from two to four weeks old a very large part of the 
whole ovary consists of egg-clusters, but at five months old there is only 
a zone of young eggs left immediately beneath the tunica albuginea.* 
§ 17. The nervous system, though a unity in its fully formed 
condition, is more diverse in its origin than is the alimentary 
system. The latter system, as has been shown, arises as a groove 



* See Dr. Foulis, I. c, p. 373. 



A A 2 



356 THE CAT, [chap. x. 

of the mesoblast, open downwards and lined with hypoblast, which 
gradually becomes converted into an elongated canal, from which 
secondary, more or less ramifying tubes (also lined with continua- 
tions of hypoblast) grow out. 

The nervous system also arises as a longitudinal axial groove of 
the mesoblast (lined with epiblast) extended above the alimentary 
groove and open in the opposite direction, namely, upwards. This 
groove also becomes converted into a canal and forms the basis of 
the cerebro- spinal axis, but the mass of the nerves do not arise as 
outgrowths from it, but by modification and transformation of parts 
of the mesoblast into nerve substance, such incipient nerves becoming 
attached to the independently formed cerebro-spinal axis. 

The medullary groove (except its more anterior part, which 
becomes the brain, as hereinafter described,) becomes the spinal 
marrow, as follows: — The ascending dorsal lamina? meet together 
above and convert the groove into a canal, first, in the cervical 
region. The layer of epiblast which lines the canal thickens very 
much on each side, its innermost layer (of columnar cells) becoming 
epithelium, its outer layer becoming the grey matter of the spinal 
cord, and consisting of numerous small nuclei, each surrounded by an 
aggregation of protoplasm. Outside this the white matter of the 
spinal cord is formed by transformation of the cells of the adjacent 
portion of mesoblast. The ^central canal of the developing cord 
having become relatively elongated from above downwards through 
the lateral thickening of its walls, becomes next constricted by an 
ingrowth from each such lateral wall. These ingrowths continue till 
they meet, the canal becoming thus divided by a transverse partition 
into a dorsal and ventral canal. Then the roof of the dorsal canal 
becomes absorbed, and this dorsal part of the primitive medullary 
canal (now again become a groove) is the posterior (dorsal) median 
fissure of the adult spinal cord. Meantime the white substance of 
the ventral aspect of the developing myelon grows out on each side, 
leaving, however, a median interspace which becomes in the adult 
the anterior (ventral) median fissure, which has thus quite another 
origin and nature from the posterior (dorsal) median fissure. That 
part of the primitive canal which is on the ventral side of the trans- 
verse partition (formed by the coalesced lateral ingrowths above 
mentioned,) persists as the canalis centralis of the spinal cord of the 
adult. The cervical and lumbar enlargements of the spinal cord 
soon make their appearance, and the canalis centralis is also some- 
what enlarged in those two regions. The myelon is at first 
co-extensive with the neural canal of the skeleton, so that there is 
no cauda equina. Afterwards, however, its growth does not keep 
place with that of the skeleton, and thus the roots of the hindermost 
spinal nerves become more and more elongated, and the formation 
of a cauda equina thence results. 

At its proximal end the spinal cord merges into the medulla 
oblongata by the thickening of the floor and sides of the primitive 



chap, x.] THE DEVELOPMENT OF THE CAT. 



557 



groove and the approximation of the roof of the canalis centralis to 
the dorsal surface. 




fm " pv o 

Fig 160. — Diagram of Brain Development, to show the essential relations of its parts. 



A. The brain in its earliest condition of three 

hollow vesicles, the cavity of which is con- 
tinuous with the wide cavity (d) of the 
primitive spinal marrow (m). The brain 
substance forms an envelope of nearly equal 
thickness throughout. The wall of the 
anterior end of the first vesicle is the 
lamina terminalis (t). 

B. Here the first vesicle or fore-brain has de- 

veloped the pineal gland (jm) above, and 
the pituitary body ( pt) below, the cerebral 
hemisphere (cr) are beginning to bud forth 
from the front part of the first vesicle. 

C. The cerebrum is here enlarged, and has begun 

to bud out into the olfactory lobes (o). The 
cavity of the cerebrum (or incipient lateral 
ventricle) communicating with that of the 
olfactory lobe in front, and with that of the 
first cerebral vesicle (i.e., with the third 
ventricles) behind. The latter communica- 
tion takes place through the foramen of 
Monro (fm). The walls of the three cerebral 
vesicles are becoming unequal in thickness, 
and the cavity of the middle vesicle (ft) is 
becoming reduced in relative size, as the 
iter a tertio ad quartnm ventricuhim. The 
thickened upper part of the cerebrum (/) is 
what is to become the fornix. The thickened 
roof of the middle vesicle has divided into 
the corpora quadrigemina (g), and the 
roof and floor of the third cerebral vesicle (c) 
have thickened into the cerebellum (eft) and 
pons Varolii (pv). 

D. The figure shows the cerebrum more en- 

larged, with its cavity bifurcating into the 
prolongations (the cornua). The fornix has 
come to look backwards, and two lines 



(below the figure 3) indicate its prolongation 
downwards and backwards into the corpora 
mammillaria (ma). 

E. Here the cerebrum is still more enlarged, 
extending backwards over the corpora 
quadrigemina and part of the cerebellum. 
The fornix is shown bordering the descend- 
ing cornu (dc) of the lateral ventricle, and 
extending into the temporal lobe (tl). 

a. Fore-brain. 

oc. Anterior cornu 

ft. Mid-brain. 

c. Hind-brain, 
eft. Cerebellum. 
cr. Cerebrum. 

dc. Descending cornu. 

d. Cavity ot the medulla. 
/. Fornix. 

g. Corpora quadrigemina. 

i. Iter a tertio ad quartum ventriculum. 

m. Medulla oblongata. 

ma. Coi pora mammillaria. 

o. Olfactory lobe. 

pv. Pons Varolii. 

pn. Pineal gland. 

pt. Pituitary body. 

r. Crura cerebri. 

t. Lamina terminalis. 

tl. Temporal lobe of cerebrum. 

x. Space enclosed between the backwardly- 
extended cerebrum and the much narrowed 
roof of the third ventricle, which has now 
become the velum interpositum. 

2. Lateral ventricle. 

3. Third ventricle. 

4. Fourth ventricle. 



The brain is first indicated hy the expansion of the pre-axial 
end of the medullary groove into what becomes the first or most 
anterior cerebral vesicle or fore-brain. To this succeed two other 



358 



THE GAT. 



[CHAP, X. 



vesicles, namely, those of the mid-brain and the hind-brain. The 
fore-brain, called also the deutencephalon, contains the anterior 
termination of the primitive medullary canal, and this becomes the 
third ventricle ; the pre-axial wall of the first vesicle becoming the 
lamina terminalis of the adult. The optic thalami, optic nerves, 
pineal gland and infundibulum, are formed from this vesicle. 

The mid-brain, called also the mesencephalon, contains that part 
of the primitive medullary canal, which ultimately becomes the iter 
a tertio ad quartum ventriculum. The corpora quadrigemina above 
and the crura cerebri below, are formed about this ventricle. 

The hind-brain contains the cavity of the fourth ventricle, which 
is not all roofed over dorsally by nervous substance. The anterior 
part of this third vesicle is sometimes called the Epencephalon, and 
this gives rise to the pons Varolii below and the cerebellum above, the 




Fig. 161.— Four Views of the Brain of an Embryo Kitten in the stage where it first 

DIVIDES INTO THE FIVE CEREBRAL RUDIMENTS— SHOWING THE ACTUAL PROPORTIONS 
OF THE PARTS. MAGNIFIED THREE DIAMETERS. 



A. The brain, seen from above. 

B. From the side. 

C Vertical section, showing the interior. 
D. From below. 

1. Cerebral hemispheres, or prosencephalon. 

2. Region of the third ventricle— the thalamen- 

cephalon or deutencephalon. 

3. Region of the corpora quadrigemina, or 

mesencephalon. 

4. Cerebellum or epencephalon. 



5. Medulla oblongata, or myelencephalon. 

o. Optic nerves. 

V. Fifth pair of nerves. 

VIII. Glosso-pharyngeal and pneumogastric 
nerves. 

i. Infundibulum. 

vv'. General ventricular cavity, opening ante- 
riorly into the lateral ventricle by the fora- 
men of Monro. 



latter arching back and covering over the hinder part of the fourth 
ventricle. The posterior part of the third vesicle or hind-brain, is 
sometimes called the myelencephalon or metencephalon, and this gives 
rise to the medulla oblongata. 

From the anterior part of each side of the fore-brain another vesicle 
grows out. These together form the cerebral hemispheres, called also 
the Prosencephalon, which give rise to the corpora striata, fornix and 
corpus callosum. The cavity within these outgrowths are the lateral 
ventricles, and the aperture by which they are continuous with the 
cavity of the Deutencephalon (or third ventricle) is the future 
foramen of Monro. 

From the anterior part of the floor of each cerebral hemisphere 
yet another vesicle buds forth. This is the future olfactory lobe or 
nerve, called also the Rhinencephalon. Each such lobe at first like- 
wise contains a cavity continuous with that of the lateral ventricle of 
its own side ; but this olfactory ventricle is obliterated in the adult. 

The cerebral vesicles as they develope undergo a noteworthy 



chap, x.] THE DEVELOPMENT OF THE CAT. 359 

inflexion. At first they follow one another in a straight line. 
Afterwards the fore-brain and mid-brain bend downwards and for- 
wards over the front end of the notochord, while that part of the 
hind-brain which forms the cerebellum, bends upwards upon the 
portion which forms the medulla. 

The various parts which form themselves out of the three primary 
hollow vesicles, grow at very different rates. The cavities of the 
three vesicles and the olfactory lobes remain relatively small, but 
the increase in bulk of the cerebral hemispheres is much greater than 
that of the other parts. Moreover these cerebral hemispheres become 
connected together by an outgrowth of nerve substance from their adja- 
cent sides a little above the fornix, such outgrowth resulting in the 
formation of a mass of transverse connecting fibres, which become 
the corpus callosum. This transverse growth comes thus to enclose 
that space which was originally the deepest part of the great longi- 
tudinal fissure, which space is, of course, bounded on each side by a 
part of the inner wall of one of the cerebral hemispheres. These 
portions of such inner walls become exceedingly thin and form, 
together the septum lucidum, the space included between them and 
which is bounded above by the corpus callosum, becoming the fifth 
ventricle. It is plain, therefore, that the fifth ventricle is quite 
different in nature and origin from all the other ventricles of the 
brain, since these latter are remnants of, or outgrowths from, the 
primitive medullary groove and canal of the embryo, while the fifth 
ventricle, on the contrary, is as it w T ere a portion of outside space 
which has been enclosed and taken into the brain by means of those 
inward lateral outgrowths which form the corpus callosum. 

The fornix is formed by two sets of longitudinal fibres, which are 
developed (one bundle on each side,) from the upper margin of the 
foramen of Monro, while the median junction of these two lateral 
bundles form the so-called body of the fornix. Thus the fornix is the 
median part of what was originally the back or underside of the 
cerebral hemispheres, its body forming part of the outer wall or bag 
of the cerebral hemispheres enclosing the lateral ventricles. As 
these hemispheres grow backwards, the two prolongations of the 
fornix (or its posterior pillars,) extend (following the course of the 
developing " temporal lobe,") backwards and downwards, one in the 
wall of each hemisphere, as a bundle of longitudinal fibres, such 
bundle projecting into the descending course of the lateral ventricle 
as part of the hippocampus major. Its anterior pillars descend in the 
lamina terminal is to the corpora mammillaria. 

The cerebral hemispheres, with the fornix as part of their wall, 
having grown backwards over the mid-brain containing the third 
ventricle, the space between the roof of that ventricle, the velum 
interpositum, and the body of the fornix which comes to be applied 
to the velum, is thus essentially the outside of the brain, though as 
a fact it is -actually in the very middle of that great complex struc- 
ture, the brain of the adult. The velum consists only of ependyma, 
the pia mater and the arachnoid. The vascular membranes called 



360 THE CAT. [chap. x. 

choroid plexuses, are but its margins which have become very vascular, 
and the choroid plexuses of the lateral ventricles are also (as has 
been before pointed out) merely portions of the ependyma which have 
become very vascular, and are by no means intrusions from without 
into the true cerebral cavity. The vascularity is, in fact, continued 
on in that portion of the ependyma which lines the foramen of Monro 
and the lateral ventricles. The membranes which invest the brain 
externally never enter the ventricles at all, but are (as has been 
already said) reflected back on the under surface of the fornix. 

The third ventricle, which has (as has been said) the velum 
for its roof, grows out below into the infundibulum. The pineal gland 
is formed in connexion with the roof of the third ventricle from behind 
the velum. The pituitary body comes from the mouth — see p. 343. 

The sides of the third ventricle, unlike the rest of its walls, 
become greatly thickened to form the optic thalami, while its 
anterior wall, the lamina terminalis, becomes thickened in places and 
so forms a band of transverse fibres, the anterioTcommismre (connect- 
ing the corpora striata) and also a pair of vertical bundles (the 
anterior pillars of the fornix) extending into the fornix above, and 
into the corpora mammillaria below. The two optic thalami also 
become connected by two sets of transversely extending nervous 
structures. The first and more anterior is formed of grey matter 
and is called the soft commissure, the more posterior, formed of 
nerve fibres, is called the posterior commissure. The corpora 
quadrigemina arise as an outgrowth from the roof of the mid- 
brain, and one con-taining* a cavity continuous with that of the, 
second cerebral vesicle. The corpora are at first of very large 
relative size, but they seem, as it were, to lag behind in growth, 
become solid, and ultimately divided, first into two lateral halves, 
and ultimately into nates and testes. 

Concomitantly with the development of the corpora quadrigemina, 
the floor of the mid-brain becomes greatly thickened by the develop- 
ing crura cerebri, and thus the primitively large cavity of the 
mid-brain becomes reduced to the very narrow iter a tertio ad quar- 
tum ventriculum. 

Each cerebral hemisphere is also a bag, the walls of which 
are very unequally thickened. Part of the inner wall, along the 
descending cornu, is reduced to mere ependyma, with pia mater and 
arachnoid, so that it tears very easily, the rupture thus produced 
having (in man) been called the fissure of Bichat and taken for a 
natural opening. Each corpus striatum is a thickening of the outer 
and under wall of each hemisphere abutting against the front and 
outer part of the optic thalamus behind it, and forms the axis round 
which the whole hemisphere is developed. 

Slight depressions begin sooner or later to appear on the surface 
of each hemisphere, the beginnings of the future gyri and sulci. 
These increase very gradually as the cerebrum grows upwards and 
backwards. 

The membranous ikvestments or the brain arise in different 



chap, x.] THE DEVELOPMENT OF THE CAT. 361 

modes. The dura mater is formed from the inner surface of the 
dorsal plates external to the cells which become the nervous centres. 
The pia mater and the arachnoid, on the contrary, are formed by 
transformation of the outer layer of the primitive brain mass itself. 
Thus no part of these tissues, whether choroid plexuses or what 
not, extend and grow into fossae and cavities of the brain, but they 
actually arise and are first formed there where they ultimately 
exist. 

The cranial nerves arise as four small opaque pear shaped 
masses of nervous tissue, which grow from the epiblast on each 
side of the hind brain in front of the protovertebrae on each side. 
Of these four pear-shaped masses (the wider ends of which are 
directed inwards to the axis of the body), two are placed in front 
of and two behind the auditory vesicle. The first of these masses 
becomes the fifth nerve, and bifurcates, one branch becoming the 
ophthalmic nerve, the other the 2nd and 3rd branches. The 
second mass becomes the facial nerve. The third mass becomes the 
glosso-pharyngeal, and the fourth the pneumogastric. 

The development of the eye is brought about by the con- 
currence of three different processes or growths. 1. An outgrowth 
from the brain. 2. An ingrowth from the skin. 3. An upgrowth 
of the mesoblastic tissue which surrounds the developing eyeball, 
into a certain part of its interior. 

The outgrowth of the encephalcn is in the form of a hollow 
process of the fore-brain, containing a prolongation of its cavity, 
the future third ventricle — just a3 the olfactory lobe contains at first 
a prolongation of the prosencephala cavity. This ocular outgrowth 
is called the primary optic vesicle. It ultimately developes into a 
narrow stalk and an anterior distal expansion. The stalks of the 
two primary optic vesicles are at first placed close to the junction, 
on each side, of the- cerebral vesicle with the vesicle of the third 
ventricle. Each is at first disconnected with the other altogether, 
but little by little the root of each extends over to the opposite side 
of the brain, while their fibres, where they come thus to cross, inter- 
mix together, and so a chiasm a is formed. The distal expansion of 
each primary optic vesicle gets (by apposition with other structures 
to be shortly described) doubled in upon itself, so as to become 
cup-shaped, and to present a concavity forwards and outwards, the 
secondary optic vesicle, or optic cap, while by degrees its cavity be- 
comes altogether obliterated, as also that of its stalk. 

Meanwhile a depression of the external cuticle has indicated ex- 
ternally the place of the future eye. This depression deepens while 
its lips approximate till it forms a closed sac lined by the epiblastic 
epithelium which coated the invagination. This sac becomes applied 
to the anterior cup-shaped surface of the optic cerebral outgrowth. 
The walls of the sac then thicken, especially behind, and obliterate 
its cavity. Its posterior portion certainly becomes the lens, and its 
anterior portion either also becomes part of the lens, or is trans- 
formed into the aqueous humour which, if it is not thus formed, is 



362 



TEE CAT. 



[CHAP. X, 



formed from a growth of mesoblast intervening between the incipient 
lens and the epiblast. From the margins of the chamber of the 
aqueous humour, a growth extends inwards on all sides which 
becomes the iris, and divides the chamber into two portions. The 
vitreous humour is formed by a growth of mesoblastic tissue up 
through a fissure left below during the infolding of the primary optic 
vesicle and formation of the optic cup. This fissure gets gradually 
closed up, though traces of it, called the ocular cleft, may be discerned 
for a considerable time. The mesoblastic tissue around the eyeball 
becomes condensed into the sclerotic. The external skin in front of 






Fig. 



-Section of the commencing Eye of an Embryo, in three stages. 



Commencement of the formation of the lens 

by depression of a part of C, the epiblast. 

pr. The primitive ocular vesicle or 

nervous outgrowth from the brain, 

now doubled back on itself by the 

depression of the commencing lens (I). 

The lens depression has become enclosed, 

and the lens itself is beginning to be formed 



within it. The optic vesicle has here 
become more folded back. 
A third stage, in which the secondary optic 
vesicle — the upgrowth forming the vitreous 
lmm our (v)— begins to be formed. The 
primitive cavity of the cerebral optic 
vesicle (pi') is here reduced to a chink by 
the still further infolding of that vesicle. 



the eyeball developes a fold of membrane above and below. These 
increase in size, and become the eyelids, their inner lining and the 
epiblast coating the cornua being transformed into the conjunctiva. 
The eyelids, when formed, become glued together at their margins 
till nine days after birth. The conjunctiva is continuous with the 
lining of the lachrymal canal, which latter is a persistent remnant 
of the fissure, at first wide, which primitively exists between the 
frontal and the maxillary processes of the embryo. 

The development of the ear, in so far as it arises by involu- 
tion of the epiblast, resembles that of the eye, but it differs from it 
greatly in that there is no outgrowth from the brain corresponding 
with such epiblastic involution. The first appearance of the future 
internal ear takes place (at a very early period) on each side of the 
hind-brain, when an involution of the* epiblast forms a pit extending 
down into the mesoblast, which lies externally to the cerebro- spinal 
axis of that region. This pit deepens, and its margins close over 
and unite, so forming it into a closed sac called the otic vesicle. This 
vesicle becomes the internal labyrinth. The epiblast forms the endo- 
thelium of that labyrinth which contains the endolymph. All the 
structures external to this, namely, the fibrous structure of the 
membranous labyrinth, the perilymph, and the solid structures which 



chap, x.] THE DEVELOPMENT OF THE CAT. 363 

invest it are formed from the mesoblast. The otic vesicle sends a 
process inwards which becomes the scala media of the cochlea, w T hich 
again becomes separated off by a constriction (the future ductus 
cochlearis) from the rest of the vesicle. From other parts of the otic 
vesicle three rounded protuberances grow out, each of which becomes 
first flattened and then absorbed, except at its circumference — the 
three protuberances thus becoming the three semicircular canals. 
Two constrictions then show themselves in the wall of the large 
part of the otic vesicle, thus separating the saccule from the part 
adjacent to the semicircular canals which becomes the utricle. 

The auditory nerve is formed by direct transformation of the 
mesoblast in contiguity with the otic vesicle. It is at first distinct 
and separate both from that vesicle and from the hind-brain, though 
it grows each way, and becomes connected with both. 

The cartilage which forms the auditory capsule (investing the 
otic vesicle) is continuous with that of the basi- occipital region 
— the parachordal cartilage. This capsule becomes ossified from 
three centres, the pro- otic, opisthotic, and epiotic bones, as before 
described. These ossifications leave open two small apertures, one 
in the outer wall of the cochlea, and surrounded by the opisthotic 
bone — the fenestra rotunda — the other placed more inferiorly, oppo- 
site the vestibule, it being bounded above by the pro-otic, and below 
by the opisthotic — the fenestra ovalis. 

The external meatus, tympanum, and Eustachian tube are formed, 
as has been elsewhere said, by differentiation of the first visceral 
cleft, while the auditory ossicles are formed as has been already 
related. 

The sides and floor of the tympanum, and ultimately the floor of 
the external auditory meatus, become ossified as the tympanic bones. 

From the margin of the second, or hyoidean, visceral arch, a 
membrane grows out which becomes the external ear„ 

The development -OF the nose resembles that of the eye, inas- 
much as an involution of epiblast, the primitive nasal sac, is related 
to an outgrowth of brain-substance, the olfactory lobe of the cere- 
brum. Each of the nasal sacs deepens by outgrowth of its free 
margin, but an inequality in the growth of that margin gradually 
transforms it from a conical pit open forwards, into a groove or canal 
leading backwards and inwards. Meantime the maxillary process 
grows forwards and joins the naso-frontal process, thus bounding the 
nasal sac below ; while the external lateral nasal process bounds it 
behind — intervening, as it does, between the nasal sac and the eye. 
Thus the nasal sac comes to open behind into the front of the buccal 
cavity, but ultimately (as has been already described) the develop- 
ment (by lateral transverse growths) of the palate prolongs the nasal 
canals backwards and so causes them to open into the hinder part of 
the mouth. While this growth is going on, the ethmo- vomerine 
cartilage (formed by the anteriorly coalesced trabecule) grows down 
and embraces the nasal sacs, sending down three cartilaginous pro- 
cesses, one between and one on each side of them. The lateral 



364 THE CAT. [chap. x. 

cartilages develop processes which extend inwards, and lay the 
foundations of the maxillo-turbinal bones. In the descending plates 
of the ethmo-vomerine cartilage, the median and lateral ethmoid bones 
become developed. 

§ 18. Thus all the various parts and organs of the adult animal 
are gradually developed. But it is only by degrees that the fully 
mature form is attained, the proportions of the head, limbs, and tail 
of the kitten being obviously different from those of the full-grown 
cat. Still the young animal is substantially similar to the old, even 
in appearance, for, though blind, it is covered at birth with a hairy 
coat, more or less resembling that of one or other of its parents. 

But although the young one at birth is evidently a young cat, the 
process by which the substance of the fertilised ovum has grown into 
a kitten is a wonderfully circuitous one. For a certain time the 
embryo cannot be said to bear any resemblance to its ultimate form, 
while for a considerable period that resemblance is but a very general 
and obscure one. Even the various organs, such as the brain, 
heart, &c, are, when first formed, not the brain, heart, &c, of a 
cat, nor does the course taken by the primitive blood-vessels corre- 
spond with that of the blood-vessels of the adult. These transitory 
conditions have, however (strange as it may appear to any readers 
as yet unfamiliar with such subjects) resemblances and analogies 
with structural conditions which are permanent in quite, other crea- 
tures — in animals, that is, very different both in appearance and 
nature from the cat. 

This curious fact is one of great significance, and it is one of much 
utility to us. Its utility we shall appreciate when we consider what 
is the cat's place in nature — a question which the phenomena of its 
development will help us to determine. The full significance, how- 
ever, of the developmental process will only appear when, at the 
end of our inquiry, we apply ourselves to the consideration of 
the problem of the cat's pedigree and origin. 



CHAPTEE XI. 

THE PSYCHOLOGY OF THE CAT. 

§ 1. The word " Psychology " has been so much used of late to 
denote mental states only, that most readers will probably deem that 
by the phrase " the psychology of the cat," the phenomena of the 
cat-mind — its feelings, imaginations, emotions, and instincts — are 
exclusively referred to. 

These indeed will all be treated of in this chapter, but " Psy- 
chology," according to its original conception, and according to the 
most rational signification which can be given to the term, has a 
very much wider meaning ; for it denotes the study of all the 
activities, both simultaneous and successive, which any living 
creature may exhibit. 

On account of the very peculiar nature of a certain number of 
these — namely, all those which may be classed as " feelings " in the 
widest sense of that word — it is practically impossible to study them 
as they exist in any animal without some reference to our own 
mental activities. The study of such activities as they take place 
in ourselves, may be followed up in three modes : — 

(1.) By introspection, i.e., by the study of our own mental states, 
through our powers of reflection. 

(2.) By the study of our fellow-men as they live and act (in 
health and in disease) , drawing inferences from their words and 
gestures as to the similarity between their feelings, emotions 
and perceptions, and our own. 

(3.) By examining facts of structure — anatomical conditions — in 
order to investigate the relations which may exist between 
different mental phenomena and corresponding (normal or 
pathological) bodily conditions. 

Such of our activities — such phenomena — as we know and can 
know only by introspection, are called " subjective" and they are 
ministered to by the nervous system. That same system, however, 
also ministers, as we have seen, to many other activities of which 
introspection can give us no account, since they lie so deep that they 
are beyond its ken. 

Now it is these subjective phenomena, or, at the most, these 
together with the other activities to which the nervous system 



366 TEE CAT. [chap. xi. 

ministers, which are now ordinarily referred to by the term 
Psychology. Therefore it will be well, in studying the psychology 
of the cat, to begin with such of its activities as may seem most to 
resemble, and run parallel to, those human phenomena which are 
known to us by introspection, together with such others as may be 
most nearly allied to, or more or less inextricably mixed up with 
them. 

§ 2. We cannot of course, without becoming cats, perfectly 
understand the cat-mind. Yet common sense abundantly suffices 
to assure us that it really has certain affinities to our own. Indeed, 
the cat seems to be a much more intelligent animal than is often 
supposed. That it has very distinct feelings of pleasure or pain, 
and keen special senses, will probably be disputed by no one. Its 
sense of touch is very delicate ; its eyes are highly organized, and 
can serve it almost in the dark, and its hearing is extremely acute. 
It is obvious also that external and internal sensations — more or 
less similar to those external and internal sensations of ours by 
which we instinctively move from place to place, judge of distance 
and direction, and perceive resistance and pressure — must be 
possessed by the cat also. Were it otherwise, trees could not be 
readily ascended in search of birds, leaps could not be accurately 
taken and mice caught, walls could not be ascended and descended 
by dexterous combinations of vigorous yet delicately adjusted springs 
and graplings, nor could small apertures be skilfully passed through 
in the admirable way in which all these complexly co-ordinated 
movements are effected by the animal in question. The ease and 
grace of motion in the cat, and its neat dexterity, are a common 
subject of praise. Who ha»s not observed how cleverly a cat will 
avoid objects in its path — walking, perhaps, over a table set with 
glasses and ornaments in not very stable equilibrium, without over- 
setting any one of them. Every one knows also the great facility 
with which the cat so turns in falling as almost always to alight 
safely upon its feet. The animal's ordinary locomotion is a walk or 
a spring. It rarely runs, save when it is pursued or alarmed, and 
then it progresses by a series of bounds. When driven to it, it can 
swim, though it takes to the water, or even endures a mere wetting, 
with the greatest reluctance. Yet a cat has been seen voluntarily 
to enter a small stream several times, in order to rescue its kittens 
which had fallen into it. 

But the cat has not only external and internal sensations : the 
facts just referred to cannot be explained without also granting that 
it has memory, imagination, a power of sensible perception, and ot 
associating images in complex mental pictures which are more or less 
associated with pleasurable or painful feelings — for unless a cat 
perceived objects, it could not climb, jump, or pursue its prey. Nor 
can we doubt, when the presence of a mouse causes the impression 
of a patch of colour with a definite, familiar outline, on the retina ot 
an experienced cat, that immediately there is a revival of faint 
antecedent similar impressions, with relations of various kinds, and 



ceap. xi.] THE PSYCHOLOGY OF THE CAT. 367 

pleasurable feelings (also faintly revived) of past catchings, killings, 
tastings, and eatings. Moreover, when we recollect how common 
it is for sleeping dogs to show by slight yelps that they are dream- 
ing, we must surely admit that it is probable that cats can likewise 
dream. Nor is it impossible that when cosily sitting before a 
cheerful hearth, enjoying the heat they love so well, they may 
indulge in waking " day-dreams " also. 

As to memory, every one knows how cats attach themselves to 
their homes, and how generally they recognize at least one or two 
of the habitual inmates of their dwelling place. Everyone knows 
also how a cat, accustomed to have a saucer of milk at tea-time, 
will habitually run into the drawing-room with the servant carrying 
the tea c -tray. But even the preparatory clatter of the cups and 
plates downstairs is often enough to arouse its sensibilities, and put 
it on the qui vive. All this cannot be explained without allowing 
that the cat-mind can associate complex sets of sensuous impressions 
of different kinds — pleasurable or painful feelings being, as it were, 
the cement which binds together such complex associations. Once 
let a cat be much hurt by anyone, and it will soon show how it 
has associated a painful feeling with his image. 

But cats can so associate sensations and the images of objects in 
various relations as to draw practical inferences. My friend, 
Mr. J. J. Weir, tells me of a cat which, having been chased by boys, 
ran towards a door, jumped up, put one paw through the handle, 
and with the other raised the latch, thus causing the door to open 
and enable it to escape. This action he saw several times repeated. 
Mr. Harrison Weir has also assured me that he has seen a cat 
unfasten a latch and then open the door it fastened, by pressing 
its feet against the door-post. He has also had a cat that knocked 
at a door with the knocker — these acts being untaught, and due only 
to the cat's spontaneous acts of cognition. I have also heard of a 
cat which habitually jumped down from a staircase in such a way 
as in its descent to press with its paws obliquely on the handle 
of a door and so open it. My friend Captain Noble, of Maresfield, 
informs me that he has himself known a cat which was in the habit 
of catching starlings by getting on to a cow's back and waiting till 
the cow happened to approach the birds, which little suspected 
what the approaching inoffensive beast bore crouching upon it. 
He assures me he has himself witnessed this elaborate trick, by 
means of which the cat managed to catch starlings which otherwise 
it could never have got near. Many cats will readily learn the 
signification of certain words, and will answer to their names and 
come when called. Very strange is the power which cats may show 
of finding their way home by routes which they have never before 
traversed. We cannot explain this (as it has been sought to explain 
the like power in dogs), by the power of smell being the pre- 
dominate sense, so that a passed succession of smells can be re- 
traversed in reverse order, as a number of places seen in succession 
on a journey may be retraversed in reverse order by ourselves. On 



368 



THE CAT. 



[CHAP. XI. 



the whole, it seems probable that the power in question may be due 
to a highly developed " sense of direction," like that which enables 
some men so much to excel others in finding their way about cities, 
or that which enables the inhabitants of Siberia to find their way 
through woods or over hummocky ice, and who, though constantly 
changing the direction they immediately pursue, yet keep their 
main direction unchanged. 

In addition to all these cognitions of objects, and of the relations 
between them, cats possess strong passions and, often at least, 
affectionate feelings of personal attachment. 

The strength of their sexual feelings is notorious, and hardly less 
so is the devotion of the mother cat to her young. This latter 
emotion endures as long as she gives suck, and often, if a cat's 
second litter of kittens be destroyed while one of the previous litter 
remains, the latter will be again taken into favour, and, resuming 
its old mode of nourishment, have all the tenderness and affection 
shown to it which, was manifested towards it at first. Cats will 
sometimes (as before mentioned) show great 9 regard to individuals, 
and will manifest it by expressive gestures and slight, affectionate 
bites. These animals, then, have emotions, and they are able to 
express their feelings by external signs. Some observers have 
professed to detect more than half a hundred different expressions 
in a cat's face, but however much exaggeration there may be in 
such a statement, it isampossible to mistake their gestures of rage 
and fear at the sight of a strange and threatening dog — gestures 
well understood by the dog, and sufficient in most cases to keep him 
at a safe distance. 

But it is not only by gestures that cats express their feelings. 
Besides their hideous nocturnal howls, cats give expression to their 
desires by gentle sounds. Almost everyone must have met with a 
cat which by mewing expressed its wish for a door to be opened, or 
which thus begged for a little milk. Cats then have a language of 
their own, made up of sounds and gestures. 

Cats also have a will of their own, as all must know who have 
tried to retain on the lap, a cat minded to go elsewhere, or who have 
observed the determination with which they pursue the objects of 
their desires. 

Manifestations of quite another kind from these quasi-intellectual 
ones are, however, also shown by cats. For they possess true 
instincts* and blindly follow innate promptings in pursuit of ends of 



* One of the to us unpleasing instincts 
of the cat is that which prompts it to 
play with the captured mouse instead of 
killing it, the object and meaning of which 
have been regarded as inexplicable. My 
friend Professor Paley has made the 
following suggestion as to the true utility 
and meaning of this instinct. He 
writes: — "When we observe carefully 
the motions of a kitten in playing with 
a ball or a cork, and a string, we shall 



see that they are suggested by the very 
same instincts which are exerted by a 
cat in playing with a disabled mouse. 
In both there is the withdrawal and the 
sudden pounce, and also the propelling 
the motionless object with the claw. 
It is a mistake to suppose that a kitten 
is actuated solely by a love of sportive 
play. Those who speculate on the laws 
which allow the existence of human and 
animal suffering, alike, profess them- 



CHAP. XI.] 



THE PSYCHOLOGY OF THE CA1. 



369 



which they can have no cognition whatever. This is shown by 
both parent and offspring at birth. The young spontaneously seek, 
find, and suck from, the mother's teats, while the young mother, 
also yielding to the spontaneous promptings of her organization, 
unhesitatingly gnaws thorough the umbilical cord of her first 
kitten. 

So also a kitten brought up without any experience of mice, will 
pursue with eagerness, catch and kill the very first mouse which 
comes in its way. These instinctive acts are acts which spring 
necessarily from the structure of any organism, much as the 
actions of a steam-engine must follow their designed course 
when heat and water are duly supplied. Not, of course, that 
they are altogether such : for the steam-engine is a mere machine, 
while the animal is a living organism, endowed with much plasticity 
of body, and (as we have seen) even with a power of drawing 
practical inferences. Its instinct is, therefore, necessarily somewhat, 
as it were, plastic also, and capable, within limits, of accommodating 
itself to changed circumstances. 

Instinct, then, is a power of a kind distinct, on the one hand, from 
even such intelligence as cats * Jrave, and distinct from mere reflex 
action on the other.f Attempts have been made to deny its existence 
and distinctness, J but they have only served to make them the more 
manifest. 



selves shocked at what they call the" 
" unnecessary cruelty" of the cat. It is 
worth while therefore to inquire if there 
is not a reason that can be'given for it 
in the economy of nature. For to do this 
is better than to view the circumstance 
as one of the proofs of imperfection in 
that economy. When we consider that 
the prey of the feline race is usually 
nimble, and that it can only be caught 
by a pounce upon it, Ave shall see that 
success in catching mice, birds, &c, 
must depend on constant practice. The 
creature escapes and is recaught again 
and again, and always by a pounce. To 
make real escape impossible, the victim 
is nipped or disabled, but generally so 
slightly that it may at first be taken 
from the cat very little injured. It is 
clear that each capture is thus made a 
lesson in catching. For everything 
depends on the sudden and noiseless 
dash." 

* Mr. Douglas A. Spalding found 
kittens to be imbued with an instinctive 
horror of the dog before they were able 
to see it. He tells us : — " One day last 
month, after fondling my dog, I put my 
hand into a basket containing four blind 
kittens, three days old. The smell my 
hand had carried with it set them puff- 
ing and spitting in the most comical 
fashion." (Nature, October 7, 1875, 
p. 507.) 



+ " Instinct, as instinct, is of course 
an abstraction existing in the mind, 
though it exists concretely enough in 
animal actions of a special Hnd. In- 
stinct is, concretely, the animal organism 
energizing in certain ways." "It is a 
faculty of the feeling, imagining, organi- 
cally-remembering and autoniaticaihy- 
acting soul, which faculty is in most 
intimate connection with "the organiza- 
tion of each species, so that upon the 
recurrence of certain sensations, external 
or internal, a definite series of actions is 
initiated, for the performance of which 
the organization has been specially de- 
veloped. It is action like reflex action, 
save t'hat it takes place in consequence 
of feelings and iniHginations. It is so 
intimately related to an animal's struc- 
ture, that if it were possible for us to 
construct any given kind of animal, we 
should necessarily give rise to the in- 
stinct in giving rise to the structure.' 
(Lessons from Nature, pp. 236 and 
239.) 

X Mr. Herbert Spencer and the late 
Mr. Lewes agree in entertaining very 
singular views as to instinct. According 
to Mr. Spencer, it is a higher develop- 
ment of reason, which it has replaced 
owing to the establishment of a more 
perfect adjustment of inner relations to 
outer relations than exists where mere 
reason is concerned. Mr. Lewes regards 

B B 



370 



THE CAT. 



[CHAP. XI. 



Much below instinct are those activities before referred to as due 
to reflex action, and which exist in the cat as well as in ourselves, 
but which cannot take place without an innate power of being im- 
pressed and affected by stimuli which are not felt. 

Altogether then, the cat's active powers may be summed up 
as follows : — 

1. Vegetative powers of growth and reproduction. 

2. A power of locomotion and of motion of various parts of the 

body. 

3. A power of being impressed by unfelt stimuli. 

4. A power of responding to such impressions by appropriate 

movements — reflex action. 

5. A power of responding to felt stimuli by simple actions, plainly 

involuntary — excito-motor action, 

6. A power of blindly performing appropriate complex acts, by seem- 

ingly voluntary, actions in response to felt stimuli — instinct. 

7. A power of experiencing pleasure and pain. 

8. A power of experiencing vivid feelings from material objects — 

sensation. 

9. A power of reproducing by mental images past feelings in a 

faint manner. 

10. A power of associating such images with fresh sensations 

according to the different relations in which they have co- 
existed— sense perception. 

11. A power of associating images in groups — imagination. 



it as "lapsed intelligence," brought 
about by the "logic ol* feeling." That 
there is a logic of feeling — that there is a 
logic in even insentient nature — is not 
to be denied ; but that logic is not the 
logic of the erystal, not of the brute, but 
of their Creator. Dr. Bastian, in his 
recent work (The Brain as an Organ of 
Mind, p. 221), also endeavours to show 
that instinct is not a special faculty. 
But all these writers avoid considering 
the real difficulties which oppose their 
views in either direction. Thus Mr. 
Spencer shirks all consideration of the 
phenomena which his hypothesis fails 
to explain — such as the instincts of the 
Ava-p Sphex and of the carpenter bee. 
Dr. Bastian does the same ; contenting 
himself by gratuitously asserting as to 
ants and bees (I. c, p. 235): "There 
can be little doubt, that if our means of 
knowledge were greater than it is, we 
should be able to explain these and all 
other instincts by reference to the doc- 
trines of ' inherited acquisition ' and 
'natural selection,' either simply or in 
combination." At the other end of the 
mental scale, all the highest phenomena 
are also simply ignored by all these 
writers alike. Nothing is said by one of 



them as to our apprehension of Being, 
truth, or goodness. The much to be 
lamented death of Mr. Lewes cut short 
his wnrk abruptly, so that it may be, 
had he lived, he would have addressed 
himself to the problem ; but it is strange 
that neither Mr. Spencer nor Dr. Bastian 
should have attempted to grapple with 
it. Without so doing, all their con- 
clusions may be simply disregarded, as 
the phenomena they notice are all beside 
the main issue they profess to raise. As 
to instinct, Dr. Bastian seeks to explain 
it by reference to the evolution of con- 
tractile hearts, oviducts, and intestines. 
But docs he mean to imply that these 
contractions were iu their first origin 
deliberate and voluntary 1 Was the 
original "desire for food " a desire which 
a creature deliberately chose to have, or 
was it developed by " natural selection," 
those organisms that had no desire for 
food becoming extinct 1 But how could 
natural selection ever originate a desire 
for food ? To what could it have been due 
but to an implanted impulse ; and if 
such an impulse must be acknowledged at 
all, why not acknowledge it with respect 
to instinct, the facts as to which so em- 
phatically demand its recognition ? 



CHIP. XI.] 



THE PSYCHOLOGY OF THE CAT. 



371 



12. A power of agglutinating and combining imaginations and 

sense -perceptions in clusters, and clusters of clusters, so forming 
more and more complex imaginations — sensuous association. 

13. A power of memory. 

14. A power of so reviving complex imaginations, upon the 

occurrence of sensations and images, as to draw practical 
consequences — organic inference. 

15. Powers leading to spontaneous impulsions in different direc- 

tions through internal or external stimuli — appetites. 

16. Powers of pleasurable or painful excitement on the occurrence 

of sense-perceptions with imaginations — emotions. 

17. A power of expressing feelings by sounds or gestures, which 

may affect other individuals — emotional language. 

18. A power of spontaneous activity in response to sensations or 

emotions — organic volition. 

§ 3. In the possession of all these varied powers, we and the cat 
are similar. But in spite of this resemblance, common sense and 
reason assure us that there is a profound difference between the 
mind of man and the highest psychical powers of the cat. This 
difference is made plain and obvious to our senses by the fact that 
we can talk, while neither the cat nor any other beast or bird has 
the gift of speech. 

It may, perhaps, be objected that it was just before declared that 
the cat has language. Now, no mistake can well be greater than 
that of confounding together two things essentially different on 
account of some superficial resemblance which may exist between 
them : to call bats, birds, or whales, fishes, would be error of this 
kind. 

The cat has a language of sounds and gestures to express its feel- 
ings and emotions. So have we. But we have further, what 
neither the cat nor any other beast or bird has — a language of 
sounds and gestures to express our thoughts ! I do not refer to 
articulate sounds. Rational language can exist without oral speech, 
and articulate sounds may be uttered (as by parrots and certain 
idiots) though reason be absent. Articulate speech (or the oral 
tcorcl) is but one mode (though much the most convenient mode) of 
making known the far more important and significant thought (or 
mental icord). It is the latter which generates the former, as we 
see again and again in each new branch of science or art, wherein 
new conceptions having been evolved, new words are coined to give 
expression to them. Men do not invent new articulate sounds first, 
and attach meanings to them afterwards, but the very reverse.* 



* Dv. Bastian, in the work lately 
referred to, has a short chapter entitled, 
"From Brnte to Human Intelligence," 
in which he considers the question of 
language, with the intention of showing 
that there is only a difference of degree 
between the mind of man and that of a 
brute. But he not only quite fails to 



show how the human intellect could 
have originated, but even gives up his 
own contention by speaking (p. 415) of 
human language as having been "started 
by some hidden and unknown process of 
natural development, or as a still more 
occult God-sent gift to man." 

B B 2 



372 THE CAT. [chap. xi. 

Great ambiguity and confusion exist as to language, six kinds of 
which may be distinguished: — 

(1) Sounds which are neither articulate nor rational, such as cries 

of pain, or the murmur of a mother to her infant. 

(2) Sounds which are articulate but not rational, such as the 

talk of parrots, or of certain idiots, who will repeat, without 
comprehending, every phrase they hear. 

(3) Sounds which are rational but not articulate, such as the 

inarticulate ejaculations by which we sometimes express 
assent to, or dissent from, given propositions. 

(4) .Sounds which are both rational and articulate, constituting 

true " speech." 

(5) Gestures which do not answer to rational conceptions, but are 

merely the manifestations of emotions and feelings. 

(6) Gestures which do answer to rational conceptions, and are 

therefore " external," but not " oral," manifestations of the 

mental ivord. Such are many of the gestures of deaf mutes, 

who, being incapable of articulating words, have invented or 

acquired a language of gesture. 

§ 4. But that the true nature of the cat-mind may be the better 

appreciated, it is desirable to recognize distinctly what are those 

human mental powers, of the possession of which by the cat no 

evidence exists. They are the following ones : — 

(1) A power of apprehending abstract ideas gathered from con- 

crete objects, such as the ideas, being, substance, unity, truth, 
cause, humanity, etc. — abstraction. 

(2) A power of apprehending external objects as such, and 

recognizing that they exist in truth — intellectual perception. 

(3) A power of directly perceiving our own existence— self - 

consciousness. 

(4) A power of turning the mind back upon what has been 

directly apprehended — reflexion . 

(5) A power of actively searching for, and so recalling past 

thoughts or experiences — intellectual memory. 

(6) A power of uniting our intellectual apprehensions into an 

explicit affirmation or negation — -judgment. 

(7) A power of combining ideas, and so giving rise to the percep- 

tion of new truths thus arrived at — intellectual synthesis and 
induction. 

(8) A power of mentally dissecting ideas, and so gaining other 

new truths, and also of apprehending truths as necessarily 
involved in judgments previously made — intellectual analysis, 
deduction and ratiocination. 

(9) A power of apprehending some truths as absolutely, positively 

and universally necessary — intellectual intuition. 

QO) Powers of pleasurable or painful excitement on the occur- 
rence of intellectual apprehensions — higher, or intellectual 
emotions. 

(11) A power of giving expression to our ideas by external bodily 
signs — rational language. 



CHAP. XI.] 



THE PSYCHOLOGY OF THE CAT. 



373 



(12) A power of, on certain occasions, deliberately electing to act 
(or to abstain from acting) either with, or in opposition to, 
the resultant of involuntary attractions and repulsions — will. 

I Now all the actions performed by the cat — all of which may be 
grouped under one or other of the eighteen groups of the former * list 
of faculties — are such as may be understood to take place without 
deliberation or self-consciousness. For such action it is necessary, 
indeed, that the animal should sensibly cognize external things, but 
it is not necessary that it should intellectually perceive their being ; 
that it should feel itself existing, but not recognize that existence ; 
that it should feel relations between objects, but not that it should 
apprehend them as relations ; that it should remember, but not 
intentionally seek to recollect ; that it should feel and express 
emotions, but not itself advert to them ; that it should seek the 
pleasurable, but not that it should make the pleasurable its deliberate 
aim. 

In fact, all the mental phenomena displayed by the cat, are 
capable of explanation by the former list of psychical powers, with- 
out the aid of any one of those enumerated in the above catalogue 
of truly rational faculties, f nor could any of the former by any mere 



* In the second section of this chapter, 
p. 370. 

f As a friend of mine, Professor Clarke, 
has put it: — "In ourselves sensations 
presently set the intellect to work ; but 
to suppose that they do so in the dog is 
to beg the question that the dog has an 
intellect. A cat to bestir itself to obtain 
its scraps after dinner, need not enter- 
tain any belief that the clattering of 
plates when they are washed is usually 
accompanied by the presence of food for 
it, and that to secure its share it must 
make certain movements ; for quite 
independently of such belief, and by 
virtue of mere association, the simple 
objective conjunction of the previous 
sounds, movements, and consequent 
sensations of taste, would suffice to set 
up the same movements on the present 
occasion." Let certain sensations and 
movements become associated, and then 
the former need not be noted : they only 
need to exist for the association to pro- 
duce its effects, and stimulate appre- 
hension, deliberation, inference, and 
volition. "When the circumstances of 
any present case differ from those of any 
past experience, but imperfectly resemble 
those of many past experiences, parts of 
these, and consequent actions, are irregu- 
larly suggested by the laws of resem- 
blance, until some action is hit on which 
relieves pain or gives pleasure. For 
instance .... let a dog be Inst by his 
mistress in a field in which he has never 



been before. The presence of the group 
of sensations which we know to in- 
dicate his mistress is associated with 
pleasure, and its absence with pain. By 
past experience an association has been 
formed between this feeling of pain and 
such movements of the head as tend to 
recover some part of that group, its 
recovery being again associated with 
movements which, de facto, diminish the 
distance between the dog and his mis- 
tress. The dog, therefore, pricks up his 
ears, raises his head and looks round. 
His mistress is nowhere to be seen ; but 
at the corner of the field there is visible 
a gate at the end of a lane which re- 
s nibles a lane in which she has been 
used to walk. A phantasm (or image) of 
that other lane, and of his mistress walk- 
ing there, presents itself to the imagina- 
tion of the dog ; he runs to the present 
lane, but on getting into it she is not 
there. From the lane, however, he can 
see a tree at the other side of which she 
was wont to sit ; the same process is 
repeated, but she is not to be found. 
Having arrived at the tree, he thence 
finds his way home." By the action of 
such feelings, imaginations, and associa- 
tions — which we know to be verce causae 
— I believe all the apparently intelligent 
actions of animals may be explained 
without the need of calling in the help 
of a power, the existence of which is in- 
consistent with the mass, as a whole, of 
the phenomena they exhibit. 



374 THE CAT. [chap. xi. 

increase of intensity, change into one of the latter, for they diner 
not in degree, but in kind. 

Into this question, however, it is not desirable, for the object of 
this work, further to enter. It is the less necessary so to do, 
because the subject has been treated at length in a book which may 
be regarded as introductory to the Author's present work. I refer 
to " Lessons from Nature as manifested in Mind and Matter," and 
especially to its 4th, 5th, 6th, and 7th chapters, in which the dis- 
tinctions of kind which exist between the mental powers of man and 
the analogous powers of brutes are considered in detail. 

§ 5. Such then, in the judgment of the present writer, are the 
most significant facts and the most important deductions with respect 
to the cat's psychology in the commonly used meaning of' that 
word. But, as has been here observed more than once, the term 
" Psychology " has and should have a much wider meaning, and 
embrace all the vital activities, of whatsoever kind, of which any 
animal is capable. 

These activities are of very different orders. Some of them are 
manifestly (like those of locomotion) activities of the entire creature. 
Others (like the activities of digestion or respiration) involve a large 
portion of the animal's body ; while others again (such as those which 
result in the formation of a nerve-cell or a blood- corpuscle) are 
activities which are confined to only very minute portions of its 
frame. 

Yet the whole of these activities must proceed harmoniously, or 
the animal could not continue to live in health and strength. Its 
body is obviously a unity. The activities of that body are in some 
way co-ordinated and unified also. To understand this fully, is 
truly to understand Psychology. 

§ 6. In the foregoing chapters we have considered both the several 
parts of which the cat's body is made up, and also the functions which 
they severally and collectively perform. We have also noted the 
successive modifications and transformations which take place during 
development—^.?., those series of forms which are assumed by the 
developing animal, between the condition of the unimpregnated ovum 
and that of the adult cat. 

We have seen (1) in the first place that the cat's body is made 
up of a collection of " systems " of organs, such as the nervous 
system, the muscular system, and the alimentary, circulating, 
respiratory, and generative systems ; (2) secondly, we- have seen that 
each such system is made up of a number of " organs," which act 
together in harmony. Thus we have seen, e.g., that the nervous 
system consists of a brain, a spinal cord, sympathetic ganglia, and 
various sets of nerves, some of these nerves energizing by the help 
of special parts, called " sense-organs " — the functions of the whole 
being some form of sensitivity. Again, the alimentary system we 
have seen to consist of a mouth with jaws, tongue and teeth, of an 
oesophagus, a stomach and an intestine with accessory glandular 
structures — the function of the whole being to minister to alimenta- 



chap, xl] THE PSYCHOLOGY OF THE CAT. 375 

Hon. So also we have seen that the cat's circulating, respiratory, 
and generative systems of parts, have each their special function, 
in the performance of which their various constituent organs har- 
moniously concur. (3) Thirdly, we have seen that each "organ" is 
made up of a greater or less number of " tissues," which together 
enable it to perform that function for which it is destined. Thus 
the stomach consists of a basis of fibrous tissue, with much muscular 
tissue, and is coated internally with epithelium, which, descending 
into superficial depressions lines the various glands which open upon 
its surface. It is also richly supplied with vessels and nerves. Its 
fibrous tissue maintains its shape and gives it the strength requisite 
for its continued existence. Its muscular tissue is the source of its 
motor power, without which it could not physically act, and its 
epithelial lining, endowed with its secreting properties, is the source 
of its digestive power, without which it could not act chemically on 
the food contained within it. Its vascular structure affords the 
nutriment which its several parts need to repair the waste of its 
continued action (which action, without this supply, would soon 
come to an end), and its nervous tissue, with its property of "im- 
pressionability," is the regulating agent which adjusts the actions of 
the other tissues and of the entire viscus as one whole. (4) Fourth 
and lastly, we have seen that each separate tissue is conrposed of its 
own ultimate parts — different in each tissue, but which may, in all 
cases, be said to consist of a matrix — fluid or solid, fibrous or homo- 
geneous — with corpuscles, which are cells modified in one or another 
mode. We have also seen that each tissue is at first cellular, and 
is derived in one or another way from two layers of cells — epiblast 
and hypoblast — themselves the product of the spontaneous divisions 
of the germ-cell. Each of these cells, therefore, possesses, for a 
longer or shorter time, its own activity and plays its own part in 
contributing to the general property of that tissue of which it forms 
a minute portion. Thus w T e have : 

(a.) Cell activities, contributing to that special vital property which 
is characteristic of each tissue. 

(b.) Tissue activities, contributing to that special function which is 
characteristic of each organ. 

(c.) Organ activities, contributing to that more complex function 
which is characteristic of each system of organs, viewed as one 
complex whole. 

(d.) System activities, consisting of the combined activities of sets, 
or systems, of organs, and contributing to a higher and yet more 
complex function. 

§ 7. For just as cell activities are subsumed by that of the tissue 
they compose, and as the vital properties of tissues are synthesized 
into a higher unity by the organ of which they form a part, and as 
the functions of organs are embraced by the higher function of that 
system of parts of which such organs are members, so are the func- 
tions of all the systems of organs subsumed and synthesized into a 
yet higher unity, which is the life of the animal itself, and which 



376 



TEE CAT. 



[CHAP. XI. 



life is the function of its body considered as one whole, just as the 
subordinate functions are those of that body's several sets of organs. 

That the living cat is one creature in feeling and action, as well 
as that its body is one — i.e., that it is a unity dynamically as well 
as statically — is what common sense and reason unite to assure us. 
These suffice to convince us that the plaintive cries of its victim, the 
sight of its struggling form, and the taste of its blood, may be all 
simultaneously felt by the same cat. More than this : such sensa- 
tions call up more or less distinct reminiscences of similar feelings 
before experienced, and give rise to vivid emotions and appropriate 
actions, so that past and present sensations, of very varied kinds, are 
united with different emotions and appropriate actions in one existing 
psychical activity. Such an animal then is really the theatre of 
some unifying power which synthesizes its varied activities, dominates 
its forces, and is a principle of individuation. There would seem 
to be here present, a vital force or principle, which has no organ 
except that of the entire body within which it resides, and the 
activities of which reveal that principle's existence, just as the con- 
tractions of muscular tissue make known to us its intrinsic, and 
otherwise imperceptible, power of contractility. 

§ 8. But it may be thought that in the nervous system we have 
the organ and vehicle of such unifying activity. Undoubtedly the 
nervous system is, as before said, the great regulator of the body's 
activities. But its own action requires regulation, and to be adjusted 
to the actions of other systems. It cannot, however, regulate itself! 
Moreover, all the vital activities needed for growth, sustentation, 
and reproduction, may exist in the greatest abundance without any 
trace of a nervous system, as in the great world of plants— some of 
which, such as the well-known sun -dew (Drosera) and Venus's fly-trap 
(Bioncea), very curiously simulate the actions of animals. In such 
plants we evidently have susceptibilities to impressions of a complex 
kind ; for impressions made by objects, such as insects, are followed 
by singularly appropriate actions on the part of the plants to secure 
and digest their living prey. Very curious too are those movements 
by which the roots of some plants seek moisture as if by instinct,* or 
those by which the tendrils of certain climbers appear to search 
for some fitting support, and, having found it, to cling to it by what 
resembles a voluntary clasping. ■(■ Still more remarkable is the way 



* My friend Professor Paley, tells me 
that in 1863 at Penn, near Wolver- 
hampton, a sycamore tree of consider- 
able size was found to have sent down 
into a well, to reach the water, a root 
forty-four feet long, and about a quarter 
of an inch in diameter throughout. A 
mass of roots had wrapped themselves 
round the U] per part of the well and 
nearly stopped it up. The Eev. F. H. 
Paley (formerly vicar of Penn, and now 
vicar of Church Preen, Shrewsbury) has 
confirmed the truth of this statement. 



+ These tendrils oscillate till they 
touch an object, which they then em- 
brace. The tendril of a passion-flower 
may sometimes be made to bend by the 
pressure on it of a thread weighing no 
more than the thirty-second part of a 
grain, or by merely touching it for a 
time with a twig. If, however, the twig 
be taken away again at once, the tendril 
will then soon straighten itself. Yet 
neither the contact of other tendrils of 
the same plant or the fall of raindrops 
will produce such bendings. 



chap xi.] 1HE PSYCHOLOGY OF THE CAT. 377 

in which the little creeping plant, the "mother of a thousand " 
(Linaria), explores the surface of a wall to find an appropriate 
hollow for her progeny, which hollow being found, her capsule is 
plunged in it, and its seed is there discharged. Here, therefore, there 
a co ordination of actions for the benefit of the whole organism, and 
yet in no plant is there a trace of a nervous system. 

§ 9. The existence in each animal of an internal principle of 
individuation and co-ordination is indicated by various anatomical 
and pathologjcal FACTS. We have seen the bilateral and serial 
symmetry which exists in the cat's body and limbs. Relations of 
symmetry of similar kinds show themselves also in abnormal and 
diseased conditions. Sir James Paget,* in treating of symmetrical 
diseases, mentions a lion's pelvis which was marked, through a sort 
of rheumatic affection, by a pattern more complex and irregular 
than the spots upon a map, yet so symmetrically disposed that 
all spots or lines on one side of the pelvis were exactly repeated by 
those on the other side. He also observes that diseases very often 
affect simultaneously 7 such homologous parts as the backs of the 
hands and feet, the palms of the hands and the soles of the feet, 
the elbows and knees, and the corresponding parts of the upper arms 
and thighs. 

As to monstrosities, M. Isidore Geoffroy St. Hilaire remarks : * 
"L'anomalie se repete d'un membre thoracique au membre ab- 
dominal du menie cote," and quotes a case in which certain corre- 
sponding parts of the carpus and tarsus, the metacarpus and 
metatarsus and of the digits, were simultaneously absent. 

Professor Burt Gr. Wilder has recorded f no less than, twenty- 
four cases where such excess co-existed as regards both little fingers ; 
six in which both little fingers and toes were similarly affected, and 
twenty -two cases more or less the same, but in which the details 
were not accurately to be obtained. 

Perhaps, however, the most curious and instructive cases are 
those presented by some of our domestic birds. In trumpeter 
pigeons, and some bantams, the feet, which are usually naked, 
become abnormally feathered, and these feathers may even exceed in 
length those of the wings. They are also developed from that side 
of the foot which corresponds with the feather-bearing side of the 
hand. Moreover, in ordinary pigeons, though the digits of the 
hand are completely united together, the toes of the foot are free. 
In these abnormal pigeons, however, the outer toes become more or 
less united together by skin like the fingers. 

Facts such as these, seem to make evident the existence in each 
animal, which as a whole is a visible unity, of an innate polar force 
tending to carry out development in definite directions, but liable to 
have its effects modified by the action of surrounding circumstances. 



* Lectures on Surgical Pathology, j p. 228. Bruxelles, 1837. 
1853, vol. i., p. 18. I X Massachusetts Medical -Society, 

t Hist. Generale des Anomalies, t. i., | vol. ii., No. 3, June 2, 1868. 



378 THE CAT [chap, xi.; 

All such animals however, as those just mentioned, have a well 
developed nervous system ; but there are other animals in which 
symmetry of form is carried to the highest degree, while yet no 
trace of a nervous system is to he detected in them. 

Such creatures are the Radiolarians — minute marine organisms of 




Fig. 163.— DORATASPIS POLYANASTEA. ADULl 



almost the simplest structure as regards their soft substance, but 
which have siliceous skeletons of extreme complexity and beauty, 
and, at the same time, of marvellous symmetry. 

§ 10. In such an animal as the cat, then, we have indeed evidence 
of a principle of individuation ; for in it we have not only symmetry 
of organization and harmonious organic action (as in the lowly 
organized creatures just referred to), but also sense perceptions, 
which meet in a central sensitive faculty able to discriminate the 
odorous from the coloured and the sapid from the audible. 

Not that there is any reason to think that the cat can appreciate 
the odours, &c, as such, but only that it is practically impressed by 
the relations and distinctions between its own sensations as well as 
between the objects which elicit them. It has, in fact, not con- 
sciousness but " CONSENTIENCE." 

§ 11. But, as we have seen, its nervous system ministers to a 
vast number of actions which are unfelt as well as to its felt actions, 
while its life is also made up of actions which the nervous system 



CHAP. XI.] 



THE PSYCHOLOGY OF THE CAT. 



379 



cannot control. Such are the actions within the nervous system 
itself, and the changes which take place in the ultimate substance 
of the other tissues beyond the reach of the finest vessels or the 
most delicate nerves. 

Some actions (such as those above referred to) we know, by our 
own experience, are "felt" actions — the " subjective " and im- 
material pbenomenon taking place simultaneously with the bodily 
change v But no physiologist can deny but that other nerve actions, 




fig. 164.— dorataspis polyanastra, young. showing its multipolar modk of growtu. 
The spherical shells are formed by outgrowths, which spring from tdk 
radiating parts at similar distances from the centre of the shell, the 
lateral extensions from the radii meeting to form a sphere by their 
junctions. 

which are not felt, may have their quasi-subjective or immaterial 
sides also. More than this : to be rational, we must admit that every 
action of any animal really has its quasi- subjective or immaterial side. 
Mr. Bain has said,* " It would be incompatible with everything 
we know of cerebral action, to suppose that the physical chain [of 
phenomena] ends abruptly in a physical void, occupied by an im- 
material substance ; which immaterial substance, after working 
alone, imparts its results to the other edge of the physical break, 
and determines the active response — two shores of the material, with 
an intervening ocean of the immaterial." This is good as far as 
it goes, but the converse is at the least as inconceivable — namely, a 
break in the immaterial chain, bridged over by the intervention of 
a physical substance. Moreover, what Bain here affirms with respect 
to the brain and its activity, must, by any logical py sonologist, be 
also affirmed with respect to every entire living organism and its 
activity. We find in each organism a chain of physical phenomena 



* Mind and Body, p. 13. 



380 



THE CAT. 



[CHAP. XI 



accompanied by a chain of immaterial energies, some part of which 
Ave know in ourselves as conscious feeling and thought ; but the rest 
of w T hich, in ourselves, and in all other living creatures, we can 
only know by rational inference. The chain of physical phenomena 
consists of the actions of that side of the one living whole, which we 
call its visible body. The chain of immaterial energies consists of 
the actions of that side of the one living whole which is its principle 
of individuation, its "psyche," or "soul." 

§ 12. The word "soul" must not be understood to denote that 
which it has been, in modern times, commonly used to express. By 
it is not meant a substance numerically distinct from the animal's 
body, and which may be conceived as capable of surviving the des- 
truction of the latter * — a conception which is unphilosophical as 
well as unscientific. 

We have seen that structure and function ever vary together, just 
as the convexities and concavities of the same curved line do and 
must vary together. In the same way the " principle of individua- 
tion," or "soul," of any animal (and of any plant either), and its 
material organisation, of which that soul is the " function," must 
necessarily arise, vary, and be destroyed simultaneously, unless some 
special character, as in the case of man, leads us to consider it ex- 
ceptional in nature. The word "soul," then, as here used, and as 
used by Aristotle and his followers, does not denote a separate entity 
which inhabits the body — an extra- organic force within the living 
creature, and acting by and through it, but numerically distinct from 
it. It denotes that which as considered apart from the body is but 
a mental abstraction, but which, considered as one with the body, 
exists most truly and really as an inseparable part of one indivisible 
whole — the living body. It and the body are one, as the impress on 
stamped wax and the wax itself are one, though we can ideally dis- 
tinguish between the two. Our common sense assures us of that which 
science and philosophy confirm, namely, that a living animal is not 
a piece of complex matter played on by physical forces from without, 
which transform themselves in passing through it ; but is the ex- 
pression of a peculiar immanent principle (whensoever and however 
arising), which for a time manifests its existence by the activities ot 
the body with which it is so entirely one that it may much more 
truly be said to be the animal than the lump of matter which we can 
see and handle can be said to be such animal. 

Thus the real, substantial constituent essence of the animal we are 
studying — as of every other animal — is not what we see with our 
eyes ; it is something which ever escapes our senses, though its 
existence and nature reveal themselves to our intellect. It neces- 
sarily escapes our senses, because these senses can detect nothing in 



* Even in man, there is no adequate 
reason for believing in the existence of 
any principle of individuation, save that 
which exerts its energy in all his func- 
tions, the humblest as well as the most 



exalted, though there is good evidence 
of a philosophical kind that in his case 
that principle does survive the dissolu- 
tion of the body. 



chap, xl] THE PSYCHOLOGY OP THE CAT 381 

an animal or plant beyond the sensible qualities of its material com- 
ponent parts. But neither is the function of an organ to be de- 
tected save in and by the actions of such organ, and yet we do not 
deny it its function or consider that function to be a mere blending 
and mixture of the properties of the tissues which compose it. 
Similarly it would seem to be unreasonable to deny the existence of 
a living principle of individuation because we can neither see nor 
feel it, but only infer it. This power or polar force, which, is im- 
manent in each living body, or rather which is that body living, is 
of course unimaginable by us, since we cannot by imagination 
transcend experience, and since we have no experience of this force, 
save as a body living and acting in definite ways. 

§ 13. It may be objected that its existence cannot be verified. 
But what is verification ? We often hear of " verification by sensa- 
tion, " and yet even in such verification the ultimate appeal is not 
really to the senses, but to the intellect, which may doubt and which 
criticises and judges the actions and suggestions of the senses and 
imagination. Though no knowledge is possible for us which is not 
genetically traceable to sensation, yet the ground of all our de- 
veloped knowledge is not sensational, but intellectual, and its final 
justification depends, and must depend, not on "feelings/'' but on 
" thoughts.'' " Certainty " does not exist at all in feelings any more 
than doubt. Both belong to thought only, " Feelings " are but the 
materials of certainty, and though we can be perfectly certain about 
our feelings, that certainty belongs to thought and to thought only. 
" Thought," therefore, is our absolute criterion. It is by self- 
conscious thought only that we know we have any feelings at all. 
"Without thought, indeed, we might feel, but we could not know 
that we felt or know ourselves as feeling. If then we have rational 
grounds for recognizing the existence of this " soul " — and its exist- 
ence is made known to us by its acts, and is verified by our reason — 
then, the poverty of our powers of imagination should be no bar to 
its recognition. We are continually employing terms and con- 
ceptions — such, e.g., as "being," "substance,"" cause," &c. — which 
are intelligible to the intellect (since they can be discussed), though 
they transcend the powers of the imagination to picture. 

On all sides things made known to us by sense (sensibles\ serve to 
elicit conceptions of things which can be apprehended by the intellect 
(intelligibles), but can never be themselves directly perceived by the 
senses. As they cannot be so perceived, they can never be imagined, 
but can only be symbolically expressed by words or other signs. 
Such signs must always be inadequate to express what they are 
intended to symbolise, because we can use no signs which are not 
transcripts of sense, while what they are intended to symbolise, 
is, as we have seen, beyond sense. Such symbols, therefore, are 
necessarily open to the cavils of any one who professes not to have 
the ideas they serve to express, and who asks for sense-impressions 
absolutely equivalent to such ideas ; since none such can there be. 
But no objection can hence be drawn against the conception of the 



382 THE CAT. [chap. xi. 

" animal soul," which is not equally valid against all those concep- 
tions, " cause," " being," " substance," &c, without the acceptance 
of which, our intellectual activity must come to an end altogether. 

This principle of individuation, then, this soul, or \/a>x?7, animates 
the whole body, and presides over all its actions ; which are, indeed, 
its actions, the body, as a whole, being its "organ" — the function 
of such " organ " being the " soul's action " or " life." Not to admit 
this is to be driven to the absurdity of conceiving the living body to 
be made up of an indefinite quantity of minute independent 
organisms, without subordination or co-ordination, each with its own 
principle of individuation, its own soul.* This conception, indeed, 
but multiplies difficulties, since the same arguments can be brought 
against each of these souls, or against the one soul, while to affirm 
their existence and deny functional unity, is to contradict the direct 
evidence of our senses as regards other organisms, and even the 
evidence of consciousness itself as regards our own ; for each man's 
own feelings and perceptions declare to him that he is one whole — ■ 
a living unity in multiplicity. 

§ 14. But some writers who fully recognize the fact of the two co- 
existing cycles of animal life (the physical and the immaterial) have 
regarded the latter (the immaterial) as the mere effect of the former 
(the physical), and have denied to the feelings of animals, or to the 
thoughts of men, any power to act as causes in the events of life — 
both animals and men being regarded as mere automata. But the 
notion that an animal is really a machine is an absurdity ; for a 
machine is a complex structure, the actions of which are fully to 
be accounted for by the physical properties of its component parts 
and the action of merely physical forces — without the intervention 
of sensation, or of any influences like those which induce nutrition 
and reproduction in living creatures. A clock, to be really compar- 
able with an animal, must be capable of winding itself up, gathering 
oil to replace that which is used up in its movements, repairing any 
trifling injuries which may result from the friction of its wheels, 
and finally, of giving forth from time to time miniature reproductions 
of itself destined ultimately to attain the size of the parent timepiece. 

Now an animal such as the cat, is a complex structure which 
really has all these powers, and its parts are, as we have seen, so 
mutually adjusted to serve one another, that it may be said to be a 
mechanism the parts of which are reciprocally ends and means. 
The nervous system ministers to the circulation, the circulation to 
the nervous system, and both these to the alimentary system which 
nourishes them again ; and so on throughout the whole complex 
collection of apparatus which make up the cat's body. 

But that body is one which, like a machine, does act mechanically 
and necessarily, because its actions are necessarily determined by the 
adjustments of its various parts. Yet its actions do not take place 
without sensations, and these sensations are not the mere accom- 

* As has been affirmed by Professor Haeckel. 



chap, xi.] THE PSYCHOLOGY OF THE CAT 383 

paniments of bodily actions, but are themselves guides and directing 
agencies which intervene and operate upon, though they do not 
break through, the circle of its bodily actions. The feeling of the 
blow of a stick, or the sight of a threatened blow, will change the 
course of action which a cat would otherwise have pursued. That it 
is the feeling or the sight of the stick, together with the various 
passed feelings or imaginations which such fresh experience calls up, 
which causes the change, will be disputed by no one who has not 
some eccentric thesis to maintain. 

But the movements of the animal are also determined (like our 
own) by a multitude of organic influences which are not felt, though 
they operate through the nervous system (being thus parallel with 
those which are felt) and form part of the immaterial chain which 
accompanies the chain of physical modifications which take place 
during its life. Thus, again, we see that the animal is a creature of 
activities which are partly physical and material, partly psychical 
and immaterial, of which the latter — both the felt and the unfelt — 
are directive, though they are in turn influenced by physical modifi- 
cations. We may compare this reciprocal influence to the altera- 
tions in the shape of a ring formed of two inseparably united metals 
which contract unequally at the same temperatures — alterations 
in either constituent affecting the compound whole, and therefore 
affecting the other constituent also. 

The notion that an animal is a mere automaton in which the 
physical action alone enters into the chain of causation, has been 
supported by comparing its psychical activities to mere collateral 
products of the working of a machine, such as the sound of the 
steam engine's whistle. Against this, Mr. Lewes has urged* as 
follows : " The feeling which accompanies or follows a particular 
movement cannot, indeed, modify that movement, since that is 
already set a going, or has passed ; but the analogy fails in the 
subsequent history : no movements whatever of the steam engine 
are modified by the whistle which accompanies the working of that 
engine ; yet how the reflected influence modifies the working of the 
organism ! If the hand be passing over a surface, there is, accom- 
panying this movement, a succession of muscular and tactile feelings 
which may be said to be collateral products. But the feeling which 
accompanies one muscular contraction is itself the stimulus of the 
next contraction ; if anywhere during the passage the hand comes 
on the surface which is wet, or rough, the change in feeling thus 
produced, although a collateral product of the movement, instantly 
changes the direction of the hand, suspends or alters its course — that 
is to say, the collateral product of one movement becomes a directing 
factor in the succeeding movement." This is what no automaton could 
effect. Sensation is of the essence of the process, and is evidently 
a " cause." 

What light is thrown upon this subject by our own knowledge of 

* Physical Basis of Mind, p. 407. 



384 THE CAT. [chap. xi. 

ourselves ? We know that in our own actions sensations enter as 
causes as well as accompaniments of our activity, and not only this, 
for we know further that our thoughts may also enter into the same 
circle of our life changes. We know that it is our knowledge that a 
certain event is imminent {e.g., that a storm is fast approaching) 
which makes us act in a certain way (e.g., to stop in a walk 
and begin to return towards home) in anticipation of it. To deny 
this is to deny the evident teaching of our consciousness — it is to 
deny what is most evident in favour of what is much less so — some 
speculative hypothesis. Let us suppose that some one tells us when 
away from home that our house is on fire, who does not know that 
the actions he thereupon performs are due to his mental apprehen- 
sion of the news told him ? If we do not know such a thing as this 
we know nothing, and discussion is useless. As the late Mr. Lewes 
has said,* " That we are conscious, and that our actions are de- 
termined by sensations, emotions, and ideas, are facts which may or 
may not be explained by reference to material conditions, but which 
no material explanation can render more certain." The advocate of 
"Natural Selection " may also be asked, tf How did knowledge ever 
come to be, if it is in no way useful to its possessor, if it is utterly 
without action, and is but a superfluous accompaniment of physical 
changes which would go on as well without it ? " 

§ 15. But let us learn a little more from our own experience of 
our own nature. We know that a whole multitude of actions, 
which are at first performed with attention and a full consciousness, 
come at last to be performed unconsciously ; we know that effective 
impressions may be made on our organs of sense without our know- 
ledge — our attention at the time of the occurrence being diverted. 
We know also that countless organic activities take place in us under 
the influence and control of the nervous system, which either never 
rise into consciousness at all, or only do so under abnormal con- 
ditions. Yet we cannot but think that those activities are of the 
same generic nature, whether we feel, perceive, or attend to them or 
not. The principle of individuation in ourselves, then, evidently 
acts with intelligence in some actions, with sentience in many 
actions, but constantly in an unperceived and unfelt manner. Yet 
we have seen that it undeniably intervenes in the chain of physical 
causation. 

The principle of individuation in the cat is a principle which 
subsumes into a higher unity, which unifies and directs the active 
properties of all the cells and tissues, and the functions of all the 
organs and system of organs which make up the animal's corporeal 
frame. Its activities are : (1) mainly unfelt and occupied with the 
simplest vital processes of the organism. Amongst these there is 
much organic discrimination, and that automatic memory of the 
organism which, is, as it were, the basis of that felt memory which 
intervenes in the animal's mental activity ; (2) They are those 

* See Physical Basis of Mind, p. 383, 



chap, xl] THE PSYCHOLOGY OF THE CAT. 385 

various feelings and emotions which, make up its mental powers. 
Common sense is right, then, when it says " the cat sees, the cat hears, 
the cat feels, the cat runs, plays, hunts," &c. ; for it is the whole living 
organism which does all these things, and not merely its brain, 
muscles, or any portion of that inseparable unity of which it consists. 
Moreover, it is the invisible, immaterial entity which ever escapes 
our senses but which is visible to our reason, which is more truly and 
emphatically the cat itself, than is the matter of which it is com- 
posed. The energy, direction, and control belong to it, and without 
it the cat is not. The dead body of the cat we may anatomise at 
will, but the animal itself being dead has no existence, any more 
than a " corpse " is a " dead man." 

The dead body of a man is a perfectly correct expression, but to 
speak of a dead man, a dead cat, or a dead bird, though, of course, 
fully permissible in popular speech, is really and philosophically to use 
an expression as self-contradictory as it would be to say a " dead 
living creature." 

§ 16. The difficulty which some readers may possibly feel in 
conceiving the real existence of a distinct and substantial but (in 
itself) immaterial entity subsisting indivisibly as an innate principle 
in every living organism, is due rather to the prejudice induced by 
a popular tendency than to any reason which can be logically urged 
against it. " Sensationalism " is the vice of the day which tends to 
degrade our art and literature as well as our science. "We see it 
welcomed on the stage by crowds of sympathetic auditors, and this 
craving of our lower impulses is copiously fed by the less scrupulous 
of our novelists. 

Although it is the special dignity and prerogative of man, amongst 
animals, to apprehend the abstract and ideal, his tendency too often 
is to repose in what is at once concrete and material. In the 
field of speculation, we recognize this materialistic tendency in 
those who refuse to recognize intellectual truths which cannot be 
verified by sense, and who forget that reason, not sense, is our 
ultimate criterion, and that it is the office of reason to criticise, and 
accept or reject the apparent testimony of the senses. 

Reaction from this irrational tendency has given rise, and gives 
rise, to a directly opposite conception. Thinkers who see clearly 
how often the essential nature of each object is misunderstood 
because it is sought for only in matter, loudly proclaim that the 
essence of everything is an " idea," and thus, in seeking to escape 
from materialism, fall into the error of idealism. 

Scientific truth, it is here contended, lies between these two 
opposite errors. It recognizes, with the first school, that the essences 
of living organism are not ideas but substantial realities. It also 
recognizes, with the second school, that such realities are not mere 
agglomerations of matter, but are the expression of an immaterial 
principle. It recognizes, in a word, that the dominant constituent 
of every living organic being is neither material nor ideal, but an 
immaterial reality which the reason can apprehend and recog- 
nize as necessarily present, but which the imagination can never 



386 



THE CAT. 



[CHAP. XI 



picture, for the simple reason that no reality of the kind can, from 
its very nature, be the object of sensible experience. 

Such an immaterial reality is that indivisible, active principle or 
individual force, which was called Psyche ' by Aristotle, and which 
we may call " soul " or " form, 5 ' in the sense of an individual living 
principle, absolutely one with the body it informs. 

§ 17. In order to make clearer what has been pointed out, it 
may be well to define more distinctly certain terms. 

The psyche or soul, then, is that principle of individuation which 
makes the animal what it is, though it has no actual existence apart 
from the matter it vivifies. Yet it is the animal par excellence, the 
matter of which it is composed being but the subordinate part of 
that compound but indissoluble unity — the living animal. 

The action of the psyche includes every vital action of the 
organism of whatsoever kind, each and every such action being a 
"psychosis " of one kind or another. 

The specially animal activity of the organism — animal psychosis — 
is the sum of all those activities to which the nervous system minis- 
ters. Every such activity — every activity of living, neural matter — 
is a neural psychosis, and ends in a feeling, a secretion or a motion. 
Neural psychosis then may be either felt or unfelt, and amongst the 
felt actions of the kind, are all sensations, memories, imaginations, 
emotions and felt impulses tending to result in action, and those 
practical inferences before referred to. The sum of felt, neural 
psychoses in the cat, is the so-called " cat-mind " or synesthesis, and 
every felt neural psychosis is a synesthetic or so-called "mental" act.* 
The remaining, or vegetative activities of the organism — vegetal 
psychosis — is the sum of all those activities which result in nutrition 
and generation — the maintenance of the individual organism and 
the reproduction of new individuals. This form of psychosis exists 
by itself in plants, but in the animal organism is most intimately 
united with animal psychosis. It is so because, as we have seen in 
the cat, the nervous system ministers to nutrition and to repro- 
duction as well as to feeling and to motion. The animal and 
vegetal psychoses are thus intimately united because the cat, being a 
true unity, can have but one principle of individuation — or psyche — 
which must therefore be the agent of all the vegetative as well as 
of all the animal psychoses which take place in it. 

§ 18. Such being the principle of individuation as made known 
to us in the adult animal, what are we to say of it in the earlier 



stages of the cat's existence ? 

* The xerms "mind" and "mental 
act 1 ' are not, of course, properly applic- 
able to the felt neural psychosis of the 
cat or of any unrational animal. They 
are here merely employed analogically 
in deference to popular usage. 

The " mind " properly denotes the phe- 
nomena of our consciousness — the rational 
soul energizing both corporeally and con- 
sciously. Such action cannot take place 



without the aid of neural psychosis to 
furnish the images or phantasmata need- 
ful for all human mental action ; but 
though so aided, the action itself is 
purely immaterial. The sum -total of 
the mental action of a rational animal 
may be called its noesis, which will be 
the analogue of the synesthesis or sum- 
total of the felt neural psychoses of an 
irrational animal. 



chap, xi.] THE PSYCHOLOGY OF THE CAT. 387 

This question cannot be duly considered without recognizing that 
though liviug creatures have principles of individuation of the most 
varied kinds, yet that they are jsusceptible of being classed in two 
groups — animals and plants. 

A^ we descend to the lowest animals, the evidence as to senti- 
ence diminishes ; while (from the resemblances of the lowest 
animals* and plants, and from the similarity of the vegetative 
functions in all living creatures) we may analogically conclude that 
activities take place in plants which are parallel with, and analogous 
to the unfelt and non-neural psychoses of animals. As Asa Gray 
has said with respect to their movements : " Although these are 
incited by physical agents (just as analogous kinds of movements 
are in animals), and cannot be the result of anything like volition, 
yet nearly all of them are inexplicable on mechanical principles. 
Some of them at least are spontaneous motions of the plant or 
organism itself, due to some inherent power which is merely put in 
action by light, attraction, or other external influences." 

Reference has already been made to insectivorous plants, such as 
Dioncea. In such plants we have susceptibilities strangely like those 
of animals. An impression is made, and appropriate resulting 
actions ensue. Moreover, these actions do not take place without 
the occurrence of electrical changes similar to those which occur in 
muscular contraction. 

Nevertheless, nothing in the shape of vegetable nervous or mus- 
cular tissue has been detected, and as structure and function neces- 
sarily vary together, it is impossible to attribute sensations, sense- 
perceptions, instincts, or voluntary motions to plants, though the 
principle of individuation in each plant acts (in .its degree) as do 
the unfelt psychoses of animals, and harmonises its various vital 
processes. 

The conception then which commended itself to the clear (and 
certainly unbiassed) Greek intellect of more than 2000 years ago, 
that there are three orders of internal organic forces, or principles 
of individuation, namely, the rational, the animal, and the vegetal, 
appears to be justified by the light of the science of our own day. 

We have no grounds for believing in the potential existence of 
sensation in plants, inasmuch as in the highest plants it is not made 
manifest, and no traces of sense organs have anywhere been found 
in them. Man apart — there are two orders of internal organic 
forces or principles of individuation — there is the animal, there is 
the vegetal, soul or psyche. 

Now we have seen that the cat begins its existence as a minute 
spheroidal mass of protoplasm, which is capable of spontaneous 
division and which can imbibe nutriment and grow. It is comparable 
with a lowly organized plant. As function varies with structure 
we cannot deny a vegetal psyche to the creature at this stage of its 
existence, though we have no grounds for attributing to it as yet a 
really animal nature. But growth continues and produces a com- 
plexity of structure which demands a principle of individuation of r, 

c c 2 



388 



THE CAT. 



[chap. xr. 



higher order. Slowly the blastoderm, is developed — the epiblast 
becomes furrowed, and the developing matter grows here and there 
into nervous and muscular tissue. We have then the organs of true 
animal life, and we are therefore compelled to conclude that, in a 
way which defies our powers of observation to detect, that vegetal 
principle which at first acted has disappeared to give place to a 
truly animal psyche. But the embryo is, as yet, no cat, neither is 
it like any other perfect animal. At first it is somewhat like a 
worm, but afterwards its visceral clefts and arches and the course 
of its blood current, show affinities (as we shall see in the thirteenth 
chapter) with the class of Fishes. These conditions disappear, and 
are succeeded by a structure which, though of a higher nature, yet 
for a time remains quite unlike that of a cat, and if the matter of 
its body is not that of a cat, neither can its inner principle be that 
of such an animal. Change, however, follows on change, till the 
activity of the principle which is operating (of whatever kind,) has 
so prepared and modified the living mass, that the embryo comes to 
assume the shape of a kitten. Simultaneously also, must that prin- 
ciple of individuation which is proper to the cat, have informed the 
embryonic structure. 

In the development of the individual therefore, we see a process 
of singular and surprising change, during which a series of transitory 
forms successively appear and disappear,* and which by such 



* These "forms" or "principles of 
individuation" must, of course, be con- 
sidered to be of a different rank and 
order from those which inform perfect, 
or fully developed, animals. They are 
"transitory forms" specially destined 
for a merely temporary existence and for 
an end beyond themselves. They have, 
moreover, an essential relation to the 
parent form which produced them, and 
which they normally reproduce. 

An embryo taken at any of the earlier 
stages of development, is certainly an 
animal of a distinct sort, but it is an 
animal of an imperfect nature, and not 
identical with any of the many kinds 
which exist permanently and indepen- 
dently. 

Some readers may object that they 
cannot imagine the advent and departure 
of such immaterial entities ; and that 
allowing that vegetal and animal 
psyches do really exist, it is more easy 
to imagine one such persisting through 
the whole series of developmental changes, 
than the succession above represented. 
Such objectors say what is quite true, but 
not to the purpose. It is not our "ima- 
gination," but our "reason," which has 
to decide such questions ; for "imagina- 
tion " is necessarily tied down to sense, 
and a "soul" of whatever kind is (like 
all that is immaterial) necessarily imper- 
ceptible by any of the senses. Facility 



of imagination is here therefore no test 
of truth, but rather the reverse. 

If, however, function and structure 
ever go together as all physiologists will 
admit, and if the existence of a soul or 
principle of individuation be ever in any 
case admitted, how, it may be asked, 
could an animal psyche co-exist with 
a merely vegetal organism, or a rational 
principle be present in a being which 
has an organisation inferior to that of a 
worm ? But even the spermatozoon and 
the unimpregnated ovum must be ad- 
mitted (on account of the internal 
activities they show in their develop- 
ment and growth) to possess some kind 
of life. Can, however, a human soul 
be believed to co-exist with either the 
one or the other ? Yet some principle 
of individuation is present in each. We 
have herein then an excellent example ot 
a succession of principles of different 
orders — a succession which cannot be 
denied by those who admit the existence 
of such entities in any case. There is 
nothing more repugnant to reason in be- 
lieving that the conjunction of these ele- 
ments results in such successive material 
transformations as prepare the advent of 
the rational psyche by the previous pre- 
sence of principles of inferior orders, 
than that their conjunction results in 
the disappearance of the two principles 
of the ovum and the spermatozoon and 



CHAP. XI.] 



THE PSYCHOLOGY OF THE CAT. 



389 



successive appearance and disappearance effect a true process of 
continued evolution — bringing about a precise, definite and pre- 
determined end by the operation of internal powers, which are 
called into active exercise in accordance with their own internal 
laws by the stimulus and co-operation of the various physical forces. 
Thus the psychology of the cat shows us that there is latent and 
potential in matter, special and peculiar substantial forms of force, 
such as the psyche of the animal we are considering, and such as 
the various lower forms which transitorily manifest themselves as 
formm transeuntes, during its process of development. It also shows 
us that the very action of one such form may be so ordered as to 
result in its own annihilation in order to give place to another, 
for the advent of which other its own activity has prepared the way, 
and which other emerges from potential to actual existence the 
moment the matter has assumed the condition apt for the new 
form's manifestation. The psychology of the cat is, as has been 
before said more than once, the physiology of the creature in its 
entirety. We shall hereafter have to consider another unity — that 
of the race — the evolution of which may, by a remote anology, be 
termed " the physiology of the species.'' Such an expression is not, 
however, exact, for a " species " is a creature of the intellect, and 
no such creature can have any real action ; whereas the individual 
animal, with its principle of individuation, is a concrete, really 
existing, and really acting entity. Nevertheless we shall presently 
see that the psychological considerations here put forward have 
their bearing upon the question as to the origin and genesis of the 
first cat and of the whole cat race. 



the advent of the rational principle at 
once. The essential notion is the same 
in either case, and the difference is but one 
of degree. To accept the latter belief, 
however, completely contradicts the 



doctrine of the necessary correspondence 
of function with structure, and harmo- 
nizes rather with the fables of mythology 
than the teachings of science. 



CHAPTEE XII. 



DIFFERENT KINDS OF CATS. 



§ 1. In the first chapter of this work the principal varieties of 
the domestic cat were shortly described, together with its probable 
ancestors, the Egyptian cat and the common wild cat. But our 
knowledge of the cat would evidently be very incomplete if no 
acquaintance were made with the various animals most closely 
related to it, which now exist or have existed, and which may 
fairly be reckoned as " different kinds of cats." 

In fact, cats of all kinds agree so closely in structure, and differ 
so decidedly, in that respect, from animals that are not cats, that 
they are universally admitted to form what is called a "very 
natural group " — that is to say, a group of animals easily charac- 
terized, and containing no members which differ strikingly from the 
other members of the group. 

But though it is very easy to say whether an animal is a cat, it 
is often exceedingly difficult to determine what kind of cat it is. 
The lion, the tiger, the leopard, the puma, and the cheetah, and 
various other kinds of cats, are very well-marked forms. No one 
can mistake any of these animals one from another, but there are 
a great many smaller cats which are in a very different case. Many 
of them vary much in colour (and somewhat in shape and more in 
size) from individual to individual. Certain kinds have received 
from different naturalists more than one name, and it is often a 
task of much difficulty to find out which is the proper name which 
any given kind ought to bear. 

To do this perfectly, it is necessary to examine the very individual 
skins which were originally described by the authors of the several 
names — which skins are the " types " of the various kinds or 
" species." When (as is very often the case) this is impossible, it 
is needful to critically examine the original descriptions, bearing in 
mind any collateral circumstances which may throw light upon the 
question as to which kind any particular author must have had in 
view when he wrote the original description. The investigation of 
this complex tangle of zoological literature is called the study of 
Synonymy, and it is often a study exceedingly difficult, on account 
of the too frequently very imperfect descriptions given by the 



chap, xii.] DIFFERENT KINDS OF CATS. 391 

proposers of new names. But there is yet another difficulty. Though 
the lion, tiger, leopard, &c, cannot be mistaken one from another, 
yet all lions are by no means alike, nor are all tigers or all leopards 
alike. They all present individual variations, and these are some- 
times so marked that certain naturalists have thought it desirable 
to distinguish one breed of lion by one name and another by another, 
and so with leopards and other species. The questions then im- 
mediately arise : (1) are these peculiar forms all "kinds" such as 
we must take note of for our present purpose ? and (2) what are 
the circumstances which should lead us to consider any given form 
as constituting a distinct " kind " of animal ? 

Now, the various breeds of cats, such as we enumerated in the 
first chapter, are called il varieties/ ' while a lion and a tiger are not 
called two "varieties " but two "species/' What is the difference, 
then, between a species and a variety ? 

§ 2. The exact philosophical signification of the term " species " 
,will be considered in the last chapter ; here, we may take it to have 
two meanings — one morphological ; the other, physiological. 
According to the first of these, it signifies a group of animals which 
are alike in appearance. If two groups of animals differ markedly 
in appearance, and if no transitional forms are known which bridge 
over, as it were, the difference thus existing between them, then 
such two groups are reckoned as two distinct " species " according 
to this first, or morphological, signification of that term, i.e., they are 
morphological species. The second use of the word " species " is to 
denote a group of animals which can breed freely amongst them- 
selves, but which, if united with animals of another appearance, will 
not produce fertile cross-breeds with them ; that is to say, they will 
not produce young which can go on indefinitely producing amongst 
themselves a race of cross-breeds as freely as either set of parent 
animals would have gone on reproducing forms like themselves. 
Creatures which are in this way restricted, are physiological species. 

As to the various breeds of domestic cats, we know that they can 
be crossed and will produce perfectly fertile mongrels, and therefore 
they are not physiologically " species," however truly each breed, 
as long as it is uncrossed, will go on reproducing its own race — i.e.,, 
will go on " breeding true." 

As to the wild cats of all kinds — lions, leopards, &c. — we know 
that some of them will interbreed and produce young, but we have 
no knowledge that such young will go on freely producing creatures 
like themselves, while, from analogy with other animals, we should 
be disposed to believe that they would not do so. Still we have as 
yet no observations to determine their specific distinctness physio- 
logically, and therefore we must as yet be content to judge of them 
morphologically, by the absence that is of intermediate forms 
between the apparently distinct kinds. Whenever new forms are- 
found so intermediate in character between two breeds previously 
reckoned as distinct species, that these new forms quite bridge over 
the difference previously supposed to exist, then the supposed two 



392 THE CAT. [chap. xn. 

species must thenceforth be reckoned as one, and that one must 
bear the older of the two names previously in use. 

There is a probability of physiological specific distinctness 
wherever there is an absence of transitional forms, for, if two kinds 
readily interbred and produced fertile offspring, transitional forms 
would, in most cases, soon abound. 

For our present purpose, then, the " kinds" of cats which we 
have to consider are such kinds as we may reasonably, on morpho- 
logical grounds, suppose to be " species " in the full sense of the 
term, and therefore, where the differences are confessedly slight and 
variable (as between different lions and different leopards), the 
creatures which present them will be reckoned as forming one 
species only. 

When, however, the evidence is very scanty and incomplete, it is 
thought well that kinds should be distinguished provisionally by 
distinct names, on the authority of different naturalists > for fear any 
really important kind should get omitted from, the list. 

§ 3. In zoology (as also in botany) each " species " has a name 
consisting of two words, which correspond with the Christian name 
and the surname of a man, except that their order is different — an 
animal's surname coming before the other name. The first word or 
term of an animal's name indicates to which " group " or " set " of 
species the animal named belongs ; and as each " group " or " set " 
of species is called a " genus," this first word is called its "generic** 
name. The second word indicates to which kind or " jspecies " of 
the genus the named animal belongs, and so this second word is 
therefore called its " specific " name. . Thus the zoological name of 
the wild cat consists of the two words, Fells catns. The first of these 
is the generic name, and indicates that the wild cat belongs to the 
group or " genus " Felis. The second word is the specific name, 
and shows that the wild cat is that kind of the genus " Felis " 
which is distinguished as " catus." 

§ 4. Following the order which is traditional, the Lion, with its 
regal and national associations, may be taken first. 

(1.) The Lion {Felis leo)* 

This powerful and well-known cat is at once distinguished from 
all others, by the familiar fact that the male possesses a " mane," 
that is to say, that the hair of the head, neck, and shoulders is 
long. The hair also forms a tuft at the end of the tail, at the 
extremity of which, surrounded by the long hair, is a small, pointed, 
harny appendage. The rest of the body is mostly clothed with short 
hair. The adult lion is of a yellowish- brown colour, without spots or 
stripes, but the colour varies in intensity, and the long hair is often 
blackish. The young are marked with little transverse dark bands 

* For a good figure of the skeleton, see De Blainville's Osteographie, Felis, plate3 
5 and 9. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



393 



on each side of the hody, and with a longitudinal black mark along 
the middle of the back. The mane begins to grow when the animal 
is about three years old, and is completed when it is about six 
years old. 

It is said to live for forty, and certainly lives for thirty, years, 
and it attains a length of 9^- feet. The animal's internal organiza- 
tion is such as has been already described with respect to the cat, 
save in certain details- Thus the pupil is round, never contracting 
into a vertical slit. The anterior cornua of the hyoid bone do not 
continue up to the skull, but an elastic ligament, about six 
inches in length, connects, on each side, the lesser cornu of the 
os hyoides with the tympano-hyaL The intestine is four times the 
length of the body.* 

The convolutions of the brain are rather more contorted than in 
the cat, and the same is the case with all the largest species of cat- 
like animals. The tapetum extends mostly below the optic nerve, 
only a small portion being above it.f The nasal processes of the 
maxillary bones end acutely, and reach backwards, on the dorsum of 
the skull, as far as, or a little beyond, the nasals. 

In the skull of one old lion J which I have examined, there is no 
trace of upper true molars, or even of their alveoli. 

The lion is not an arboreal animal, but roams over the plains of 
the countries it inhabits. It is found generally diffused in Africa, 
also in Persia and Arabia, and in Cutch and Gujerat in Western 
India. It is occasionally met with as far east as near Allahabad. 
Formerly it existed all over central India and in South-eastern 
Europe. § We have no valid ground, however, for believing that a 
large maned-cat, or lion, ever inhabited England or the adjacent 
part of Europe. 

(2. ) The Tiger [Felts tigris) ||. 

The Tiger is the largest and most powerful of all existing cats. It 
is of a bright rufous fawn colour on the dorsal surface of the trunk, 
head, and Jimbs, with vertical and with transverse dark stripes on the 
body, limbs and tail. These markings serve to distinguish it from 
every other cat. The hair of the dieeks is rather long and spreading. 
That of the ventral surface is white. The animal may attain a length 
of ten feet six inches. Its maxillary bones end bluntly, and do not 
reach as far backwards as do the nasals. The hyoid is connected to 
the skull by ligaments — as in the lion. The pupil is round, and 
never linear. Tigers that prey on cattle will kill an ox about every 



* Owen, Trans, of Zool. Soc, vol. i., 
pp. 130 and 131. 

+ Owen, Anat. of Vertebrates, vol. iii., 
p. 252. 

+ No. 4504 a, in the museum of the 
Royal College of Surgeons. 



§ Lions attacked the baggage camels 
of Xerxes when in Macedonia. 

II See D. G. Elliot's Monograph of 
Felidse, and De Blainville's Osteographie, 
Felis, plate 7. 



394 



THE CAT. 



[CHAP. XII. 



five days, and may destroy sixty or seventy head of cattle in a year. 
The tiger very seldom kills his prey by the " sledge-hammer 
stroke " of his fore-paw, so often talked about. His usual way is 
to seize it with the teeth by the nape of the neck, and at the same 
time use the paws to hold the victim and give a purchase for the 
wrench by which the tiger dislocates its neck.* It is naturally a 
cowardly animal, and retreats till provoked or wounded, and may 
even be made to drop its prey by cattle rushing at it in a body. 

It will eat animals which it has not killed, and even its own 
species, for a tiger left wounded is related to have been dragged off 
by another tiger and partially devoured, f The tigress breeds once 
a year, and has from two to five pups. Hybrids between the lion 
and the tiger are sometimes produced in captivity. 

The tiger is not an arboreal animal, but delights in thickets, 
especially near rivers. It is exclusively Asiatic, but has a very wide 
range, extending from Turkish Georgia, Mount Ararat, Persia, the 
Amoor land, and the island of Saghalien in the north, through China 
(including Corea) to the south of Hindostan, and the islands of the 
Indian Archipelago, down to Sumatra, Java, and the island of Bali ; 
but it is not found in Borneo, nor in Ceylon. 



(3.) The Leopard or Panther (Felis pardus) .% 

This animal is very variable in size and in its markings, so that 
some naturalists consider that there are several species, which 
however seem ill-defined and variable. It is generally of a yellowish 
rufous fawn colour, with many dark spots grouped in rosettes, while 
the tail is ringed and the ventral surface is whitish. The head and 
body are about three feet ten inches long, and the tail is about two 
inches shorter. 

There is a well marked variety which, though black, shows the 
usual markings when viewed in certain lights. 

Its pupil is round. The hyoid is connected with the skull by 
ligaments, and not by a continuous chain of bones. 

The leopard is an arboreal animal. Though so much smaller 
than the tiger, old women and children are not unfrequently 
killed by it. 

This species has a very wide range, being found in Africa from 
Algeria to Cape Colony, and in Asia from Palestine and Japan to 
Ceylon and Java. 

A leopard has been described by Professor Alphonse Milne- 
Edwards, under the name of F. Fonteirii,$ and is said to be distin- 
guishable by the shorter muzzle, longer and more copious fur, and 
by the markings on the flanks being more like rings than rosettes. 



* Forsyth's Highlands of Central 
Asia, p. 257. 

f Jerdon's Mammals of India, p. 94. 



X See Elliot's Mon., and De Blainville's 
Osteog., plate 8. 

§ Kecherches sur les Mammiferes, 
p. 208, plates 29, 30, and 31. 



chap, xii.] DIFFERENT KINDS OF CATS. 395 

The tail also is* shorter than the body. Two individuals have been 
obtained : one from China, the other from Persia. 




Fig. 165.— Skull of Leopard (F. pardalis). 

(4.) The Ounce (Felts uncia). 
This is a very interesting species, exhibiting to us, as it does, a 



Fig. 166.— The Odnce (F. uncia)* 

large feline animal adapted to live in a cold climate, as the mammoth 
was exceptionally so adapted amongst elephants. 

* See Elliot* s Monograph, from which the above figure has been, by kind per- 
mission, copied. 



396 



THE CAT. 



[CHAP. XII. 



It is clothed in a dense long fur, which even forms a short mane. 
It is from four to four and a half feet long without the tail, which 
measures a yard. The fur, is of a pale yellowish grey, with small 
irregular dark spots on the head, cheeks, back of neck and limbs, 
and with dark rings on the back and sides. It is whitish beneath, 
with some large dark spots about the middle of the abdomen ; the 
rest of the belly is unspotted. The long bushy tail is surrounded by 




Fig. 167. — Skull of Ounce (Felis uncia). 



incomplete black bands. The length of the head and body is four 
feet four inches, that of the tail three feet. 

The skull is very high, but concave in front of the orbit when 
viewed in profile. The nasals are remarkably short and broad. 

The pupil is round. 

The Ounce is found in the highlands of Central Asia and the 
Himalayas, where it ranges from 9000 to 18,000 feet, rarely descend- 
ing very much below the snows. It has, however, been found as 
far west as Smyrna.* It is said to frequent rocky ground, and to 
feed on wild and domestic sheep, goats and dogs, but has never been 
known to attack man. 

An animal has been described f as a new species of ounce, under 
the name F. tulliana. It seems to be more slender than F. imcia, 
with longer legs, and with a longer and narrower head. Its hair 
is also less long, thick and soft, while the annular spots are more 
numerous and smaller, and the round spots on the upper part of the 
back are smaller than those of the flanks. The tail is less thick 
and still less completely annulated. 



* Jerdon's Mammals of India, p. 101. 

+ See Valenciens, Comptes Rendus, 

1856, t xlii., p. 1035, and Tchiehat- 



cheff's Asie Min., 1856, vol. ii., p. 613, 
plate 1. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



397 



(5.) The Puma or American Lion (Felts concolor).* 

§ 5. The Puma is a large cat, somewhat like a rather slender 
lioness, as it is unstriped and unspotted when adult, and devoid of a 
mane. It is of a reddish brown or reddish grey colour generally, 
whitish beneath. The young are marked with blackish brown spots, 
which disappear at about the end of the first year. 

Its head is proportionately rather small compared with those of 
the large cats already noticed. Its length from snout to tail-root is 
generally about forty inches, and it has a tail of some twenty-six 
inches. 

The skull is remarkable for its depth anteriorly. The os hyoides 
is connected with the skull by a continuous chain of bones, as in 
the cat. 

The pupil is round. 

The puma eats deer, small quadrupeds, and the Rhea, or American 
ostrich, and sometimes destroys human life. It is said to kill by 
springing on the shoulders of its prey and then drawing back the 
head with one paw till the neck is broken. 

It is a remarkably silent animal, never roaring like the lion and 
tiger. 

It inhabits a very wide range, being spread over America from 
the Straits of Magellan to Canada, and ascending the Andes to 
9000 feet altitude. 

(6.) The Jaguar (Felis onca).f 

This is also a New World species, and the most powerful of the 
American cats. Its colour and markings are like those of the 
leopard, save that its spots are larger and more definitely arranged 
in groups, forming series of dark rings, each ring generally enclosing 
one or more spots within it. There is, however, a considerable 
amount of individual variation in the extent and arrangement of 
these markings, and the most southern forms are said to be 
generally yellow and sometimes almost white. 

In size the jaguar somewhat exceeds the leopard. 

A prominent bony tubercle exists on the middle of the inner or 
nasal edge of the orbit. :£ 

The pupil is round. 

A variety has been described § and figured by Dr. Gray as Leopardus 
Hemandesii. 



* See De Blainville, I. c, plate 6, 
and Baird's Mammals of North America. 
See also Godman and Salvin's Biologia 
Centrali-Americana, Mammalia, by E. 
R. Alston, p. 62. 

f See Elliot's Monograph, also Cuvier's 
Ossemens Fossiles, plate 34, pp. 3 and 4, 



and De Blainvilb, I. c, plate 3 ; also 
Biologia, p. 58. 

X This tubercle exists also m some 
other cats, but is not so largely or con- 
stantly developed in any other species 
as it is in the jaguar. 

§ Pro. Zool. Soc, 1857, p. 278, plate 
58. 



THE GAT. 



[CHAP. XII. 



The jaguar is a very fierce animal, and often destroys men and 
women. Its favourite haunts are the wooded hanks of rivers, and its 
habitual food is the giant rodent — the capyhara. This great cat 
ranges from the Red River, Louisiana, and the Rio Bravo, Texas, 
down to the most northern parts of Patagonia, i.e., to 40° south 
latitude. 

(7.) The Clouded Tiger (Felis macrocelis)* 

§ 6. This very handsome and interesting animal — the last of the 
series of very large cats — has a coat, the ground colour of which is 




Fig. 168.— The Clouded Tiger (Felis macrocelis). 

a brownish grey, marked with stripes and spots of black, which form 
large and irregularly disposed patches. The under parts are, as 
usual, whitish. The cheeks and sides of the head are marked with 
two parallel bands, one extending backwards from the eye to beneath 
the ear, the other more or less parallel, and passing backwards 
from above the angle of the mouth. 

The animal is about forty-two inches long from snout to tail-end, 



* See Pro. Zool. Soc, 1853, p. 192. 
Mammals of British India. 



It is described also by Jerdon in his 



OHAP. XII.] 



DIFFERENT KINDS OF CATS. 



399 



while the tail itself (which is ringed with black) is some thirty-two 
inches. 

The limbs are short compared with the body and very long tail, 
and the head is somewhat elongated compared with that of any of 
the cats yet noticed. 

The skull is very long and low. The orbit is widely open behind. 

The animal differs from all the cats yet noticed, in that it has not 
the tooth described as the first upper premolar, while that answer- 
ing to the common cat's second upper premolar is not very large. 




Fig. 169. — Skull of the Clouded Tiger (Felis macrocelis). 



The upper canines, however, are exceedingly long, longer relatively 
than in any other living cat. The upper sectorial tooth has a large 
inner cusp. 

The pupil is neither round nor linear when contracted, but has an 
oblong aperture. 

This animal affords a good example of the great individual 
differences of disposition which may exist in the same species of cat. 
One specimen in our Zoological Gardens was a most tame and gentle 
beast, while another was quite exceptionally ill-tempered and 
savage. 

The clouded tiger dwells in trees. It preys upon such animals as 
sheep, goats, pigs or dogs.. 

Its range, though extensive, is more restricted than that of any 
species yet noticed, as it inhabits only a portion of south-eastern 
Asia, from the eastern Himalayas, through Burmah, Siam and the 
Malay peninsula, to Sumatra, Borneo and Java. It also inhabits 
Formosa. One from the last-named island has been described by 
Mr. Swinhoe as a distinct species.* It is, however, only a some- 
what brighter coloured and shorter tailed variety. 

* As the short-tailed clouded tiger I Zoological Society, 1862, p. 352, plate 
(Felis brachyurus). {Leopardus bra- iZ). 
chyurus y Swinhoe, Proceedings of the I 



400 



TEE CAT. 



[CHAP. XII. 



(8.) The Thibet Tiger Cat (Fells scriptd)* 

A much smaller cat, but with markings somewhat like those of the 
clouded tiger, has been discovered in the mountains of Thibet by the 
Abbe David, and made known and named by Professor Alphonse 
Milne-Edwards, who has described it as follows: — 

General colour pale grey inclining to yellow, with reddish brown 
spots and more or less complete black margins. In the scapular 
region these spots form longitudinal, undulating bands — looking a 
little like Chinese writing. The largest of these dark lines begins 
near the inner angle of the eye, and goes thence above the ear to 
the scapular region of the back and then descending obliquely, 
widens out. A similar line, placed higher up, extends from the 
forehead to the shoulder. There are large irregularly shaped spots 
on the sides of the body. At the hinder part of the back they form 
bands and bars, not complete rings, on the tail. Part of cheek, 
neck and chest white, with transverse black markings. Belly 
yellowish, with longitudinal black marks. There are black spots 
and bands outside the legs. 

The iris is of a yellowish chestnut colour. 

Length of the head and body twenty-one and a half inches, of 
tail ten and a half inches. 

The first upper premolar is small, and appears soon to fail out, 
as on one side of the skull figured the tooth is wanting. 

It inhabits Monpin in Thibet. 

(9.) Fontakeir's Spotted Cat (Felis tristis).f 

This cat may be distinguished from the other species of the 
same countries as it inhabits, by its large size, whitish grey colour 
and large spots. It is described as follows : — 

Fur soft and long ; general colour a whitish grey. Three or four 
blackish brown lines, beginning in the centre of the head, between 
the ears, run along the whole length of the back ; rest of the body, 
flanks and legs covered with large spots of dark brown. Under- 
parts lighter than the upper, legs profusely marked and spotted with 
brown. Two bars of rufous brown pass across the upper part of the 
breast. Tail very long and bushy, rufous brown above, yellowish 
brown beneath. The upper part presenting a series of obscure dark 
brown bars. 

Length of head and body, thirty-three and a half inches ; length 
of tail, sixteen inches. 

This animal inhabits the interior of China. The skin of the 
typical specimen was bought at Pekin. 



* A. Milne-Edwards, Nouvelles Ar- 
chives du Museum, 1870, t vii., Bulletin, 
p. 92, and Recherches, p. 351, plates 
57 and 58, Fig. 1. 



t Alphonse Milne Edwards, Recherches 
des Mamniif., p. 223, plate 31 D, and 
Elliot's Monograph. 



chap, xii.] DIFFERENT KINDS OF CATS. 401 



(10.) The Bay Cat {Felts aurata)* 

This is a large one-coloured cat, and a very distinct species. It 
is from twenty-eight to thirty-one inches long from snout to tail, 
while the tail measures sixteen or nineteen inches. It is a bay-red 
above, paler beneath and on the sides, with a few indistinct spots on 
the flanks. The throat is whitish, while the tip of the tail and the 
ears, internally, are blackish. The ventral surface is reddish white, 
spotted brown. There are two black streaks on each cheek, with a 
pale black- edged line over the eyes. 

The pupil is said by Hodgson to be round. 

According to Mr. Jerdon it inhabits Nepal and Sikim. Dr. Gray 
adds as habitats, Sumatra and Borneo, and one (received by the 
Zoological Society from Amsterdam) is said to be from Sumatra. 

(11.) The Fishing Cat (Felts viverrina).f 

This well-marked and very distinct species was originally described 
by Bennett in 1833, and the type of the species is preserved in the 
British Museum. 

Its hair is short and rather coarse. Though usually of a general 
dark grey colour (darkest on the back), specimens may occasionally 
be found of a reddish grey ground tint. It is always covered with 
dark brown spots, smallest and least conspicuous on the shoulders. 
The head and back have three or four dark brown lines going 
lengthwise, which, however, upon the lower back and rump become 
broken up into spots like those on the flanks and other parts. Two 
blackish brown lines pass across the cheek, one from behind and 
one from beneath the eye, and a line of the same hue crosses the 
throat just below the chin. Throat and breast white, the latter 
crossed by three or four blackish brown lines passing from shoulder 
to shoulder. Belly same colour as flanks, spotted with blackish 
brown in continuous lines crosswise. Inside of legs greyish white, 
with from two to three dark brown bars crossing the upper part 
near the body. Tail rather short, slender, same colour as the back, 
barred above with chestnut brown, the bars going diagonally, and 
meeting in the centre, forming a V-shaped mark; tip chestnut 
brown. Underneath greyish white. Length of head and body, 
thirty to thirty-two inches ; length of tail, nine to twelve inches. 
The skull is elongated above. The orbits are completely encircled 
by bone. The first upper is present but is very small. 



* Felis aurata, Jerdon's Mammals of 
British India, p. 107 ; F. moormcnsis, 
Hodgson ; F. Temminckii, Vigors ; 
Leopardus auratus, Gray ; Cat. Brit. 
Mus., p. 12. 

+ Bennett, Pro. Zool. Roc, 1833, 
p. 68. It is described in Mr. Elliot's 
Monograph, from which the above figure 



is taken. It is also described by Jerdon 
in his Mammals of British India, p. 103. 
It is the animal named Viverriceps 
Benettii, by Dr. Gray, in his Catalogue 
of the Carnivora, p. 17, Fig. 5, and in 
Pro. Zool. Soc, 1867, p. 286, Fig. 5, 
which figure has been here reproduced. 

D D 



402 



THE CAT. 



[CHAP. XII. 



Mr. Jerdon says that the pupil is circular. He also tells us that 
F. viverrina "is found throughout Bengal to the foot of the south- 
eastern Himalayas, extending into Burmah, China, and Malayana, 




Fig. 170.— The Fishing Cat (F. viverrina) 

and that it is common in Travancore and Ceylon, extending up 
the Malabar coast as far as Mangalore." 




Fig 171.— Skull of F. viverrina. 



Mr. Buchanan says that besides fish it eats Ampullurice ^ and 
Unios, and that it has a very disagreeable smell. It is exceedingly 
fierce, and has been known to carry off children. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



403 



(12.) The Leopard Cat (Felis bengalensis) * 

There is a very distinctly spotted cat from northern India which 
is thus named by Mr. Elliot in his Monograph. Either this kind 
is subject to great variations in colour and markings, and somewhat 
also in size, or else there are several distinct species, which cannot 
yet be accurately defined for want of a sufficient number of 
specimens. 

Mr. Jerdon gives as the size of his species thus named: "Length of 
head and body twenty- four to twenty-six inches; tail eleven or twelve 




Fig. 172— Skull of F. bengalensis. 

inches and more." He says it is variable, both as to the ground 
colour and the size and boldness of its markings, though all adhere 
to one general pattern. 

The ground hue varies from fulvous-grey to bright tawny yellow, 
occasionally pale yellowish grey or yellowish, rarely greenish- ashy, 
or brownish-grey ; lower parts pure white ; four longitudinal spots 
on the forehead, and in a line with these four lines run from the 
vertex to the shoulders, the outer one broader, the centre ones 
narrower, and these two last are continued almost uninterruptedly 
to the tail ; the others pass into larger, bold, irregular, unequal, 
longitudinal spots on the shoulders, back and sides, generally 
arranged in five or six distinct rows, decreasing and becoming 
round on the belly ; two narrow lines run from the eye along the 



* See Jerdon's Mammals of British 
India, p. 105. This animal is the Felis 
pardochroa of Dr. Gray (Pro. Zool. Soc, 
1867, pp. 273 and 400 ; and Catalogue 
of Carnivora, p. 28). It is also hi* F. 
tenasscrimcnsis (Pro. Zool. Soc, 1867, 
p. 400 ; and Catalogue, p. 28) and his 
F. Elliott. The last named is only 
represented by skulls in the British 



Museum, but these are quite similar to 
the skulls of F. pardochroa. It is also 
the F. nepalensis of Dr. Gray. Mr. 
Elliot, in his Monograph, identifies his 
F. bengalensis not only with Dr. Gray's 
above-mentioned species, but also with 
his F. Wagati, as to which latter identi- 
fication I hesitate to follow him. 

D D 2 



404 THE CAT. [chap. xit. 

upper lip to a dark transverse throat-band ; and two similar trans- 
verse bands run across the breast, with a row of spots between ; tail 
spotted above, indistinctly ringed towards the tip ; the inside of the 
arm has two broad bands, and the soles of all the feet are dark 
brown. There is generally a small white superciliary line. I have 
noticed in several specimens in the British Museum, that the black 
spots unite or tend to unite over the shoulders, so as to make a 
conspicuous oval black ring, not unlike the " Vesica piscis." This 
is not, however, always to be detected. 

There is in the National Collection a skin * which came from 
the Indian Museum, and which differs considerably from all the 
specimens of F. bengalensis that I have seen, in its redder colour, 
more woolly hair, and thicker tail, as also in the less distinctness of 
its markings. It is not however in very good condition. It is said 
to have been brought from Nepal by Mr. B. H. Hodgson. The 
length of the head and body is twenty-two and a half inches ; that 
of the tail is sixteen inches. 

A first upper premolar tooth is present, but it is very small. 
The orbit is nearly encircled by bone. The post- orbital process of 
the frontal of the specimen figured has been unfortunately broken. 
F. bengalensis inhabits Nepal, Thibet, Barjeeling, Assam, Burmah, 
the Malay Peninsula, Sumatra, and Java. 

(13.) The Wagati (Felis Wagati). 

The cat in the British Museum which is thus named, is very like 
F. bengalensis ; but it is a smaller animal, and its black markings 
are more sharply defined and decidedly in the form of short black 
stripes. The animal also has not the small spots on the flanks 
which exist in F. bengalensis, and the stripes on the shoulders are 
nearly parallel and do not tend to form an oval ring. It has been 
described by Dr> Gray as follows : " Fur fulvous ; nose, chin, throat, 
and underside of body, and streak on forehead and cheek, pale 
yellow. Spots of body few, large, irregularly shaped ; of withers, 
large, elongate, broad ; of loins, elongate, narrow, more or less con- 
fluent ; tail with round spots.'' 

Length of head and body, twenty-one and a half inches. 

Length of tail, eleven inches. 

Habitat, India. 



(14.) The Marbled Tiger-Cat (Fells marmorata).\ 

This cat attains a size of from nineteen to twenty- three inches 
from snout to tail, the tail itself being about fifteen inches. It is a 
very distinct species. 



* Skin No. 79. 11. 25. 563. It is 
labelled F. Duvancelli. 

f Catolynx marmoratios, Gray, Pro. 
Zool. Soc, 1867, p. 26V ; Felis Charltoni, 



Gray, Pro. Zool. Soc, 1856, p. 396 ; and 
Catolynx Charltoni, Pro. Zool. Soc, 
1867, p. 268, and Cat. of Carnivora, 
p. 16. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



405 



The ground colour of its coat is dingy fulvous, occasionally 
yellowish grey, with numerous elongate, wavy, black spots, some- 
what clouded or marbled. On the sides of the body are large 
irregular patches of a darker shade and with dark margins, 
especially on the hinder edge of each patch. The head and nape 
have some narrow blackish lines coalescing into a dorsal interrupted 
band ; a dark line extends backwards from between the eye and the 
mouth ; the thighs and part of the sides with black round spots ; the 




Fig. 173.— The Marbled Tiger-Cat (F. marmorata). 



tail black spotted, with a black tip. The belly is yellowish white. 
The colour becomes more fulvous with age. 

There are several skulls of this species in the collection of the 
British Museum. These all agree in having the orbit nearly or 
completely enclosed by a bony ring — the postorbital process of the 
frontal meeting the postorbital process of the malar in the older 
specimens. The skull is very broad at the zygomata. The first 
upper premolar is very small, and the first lower premolar is not 
very prominent. The premaxillee ascend and join the frontals, 
thus separating the nasals from the maxillae on the surface of the 
skull. The pterygoid fossa is rather well developed. 

The pupil is said to be linear. 

This species ranges from Nepal through Burmah and Malacca 
to Java and Borneo. 



406 



THE CAT. 



[CHAP. XII. 



(15.) The Serval (Fehs Serval)* 

§ 7. This large and well-known African cat has long legs and a 
short tail. It is of a more or less tawny colour, with black spots, 
and black rings on the tail. The underparts are whitish. Towards 
the middle of the back the spots tend to run together into two longi- 
tudinal bands. There is no dark streak upon the cheek, but there 
are two strongly marked transverse black bars across the inside of 
the upper part of each fore -leg. 

The length of the head and body may be as much as forty inches, 
that of the tail may be sixteen inches. 

The pupil contracts into an oblong opening. 

There is not only a first upper premolar, but the second upper 
premolar is largely developed. 

This animal inhabits Africa from Algiers to the Cape. 



(16.) The Golden-haired Cat (Felis rutila).\ 

This species is founded upon a skin described by Mr. "Waterhouse 
in 1842, and which (the type of the species) is preserved in the 
British Museum, but is unfortunately mutilated. 

Its colour is red-brown, with indistinct small darker spots on the 
sides ; back, dark brown medianly ; belly white, with large brown 
spots ; tail red-brown, with a dark central line extending along its 
dorsal surface, while at each side it is pale, with obscure indications 
of darker bands. 

Length of head and body about twenty-eight inches ; of tail, 
fourteen inches. 

The skull has the orbits incomplete behind. There is a very 
small first upper premolar. 

Habitat, Sierra Leone and Gambia. 

There are two cats only known to me by description, as to the 
distinctness of which I am too much in doubt to venture to enume- 
rate them as distinct kinds. They are F. celidogaster and F. 
senegalensis. 

Felis celidogaster was named by Temminck,| who thus describes 

it:— 

"Fur short, smooth, shiny, grey, with a reddish tint, with 
chocolate or light brown spots; spots on dorsal line oblong, the 



* This is described and figured in Mr. 
Elliot's Monograph. 

f Waterhouse, Pro. Zool. Soc, 1842, 
p. 130 ; Gray, Pro. Zool. Soc., 1867, 
pp. 272 and 395 ; Cat. of Carnivora, 
p. 23. F. chrysothrix of Elliot's Mono- 



graph. He identifies it with both the 
F. aurata and the F. celidogaster of 
Temminck, and with the F. neglecia of 
Gray. 

£ Esquisses Z .ologiques, p. 87. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



407 



others round ; cheeks and lips whitish, with small hrown spots ; 
throat and chest with six or seven half- circular hrown hands ; lower 
parts and inner sides of the limbs pure white, with large round 
chocolate-brown spots ; two bands of this colour on the inner side of 
the fore, and four on the hind feet ; tail hay-brown, with paler 
brown rings, end black brown ; outer surface of the ears black ; 
claws white." 

Length of body and head, twenty-six inches ; that of tail, fourteen 
inches. 

Mr. Elliot identifies this with the F. negleda of Gray and the 
F. ridila of Waterhouse . (P. Z. S. 1871, p. 759), and describes it in 
his Monograph under the name F. chrysothrix. 

The other doubtful species is Felis senegaknsis of Lesson* The 
fur of this animal is of a uniform reddish grey, paler beneath, with 
black spots inclining on the back to run into longitudinal stripes ; 
spots on limbs ; tail ringed ; two black stripes from eye to ear ; 
muzzle, chin, and throat white. 

The individual described was about the size of the domestic cat, 
and was regarded as probably immature. It seems probably to 
have been a young Serval. 

Habitat, Senegal. 

As to this species or variety Professor Alphonse Milne-Edwards 
has been so kind as to inform the author that no specimen of it 
exists in the Paris Museum. The original description was made 
from a living animal at the hospital of Eochefort-sur-Mer. A 
young Serval in the Paris Museum closely resembles the description 
of F. senegalenm, but has a tuft of hairs on each ear. 



(17.) The Grey African Cat (Felis neglecta).\ 

This is rather smaller than the last species, and is well distin- 
iguished by its grey colour. The type is in the British Museum, 
and was originally described by Dr. Gray as follows : — 

" Grey ; head and body marked with numerous small darker 
spots, spots of the lower part of the sides rather larger ; beMy white, 
with large blackish spots ; tail quite half the length of the body, 
with a dark line along the upper surface, sides paler, with obscure 
indications of darker bands." 

No dark streak on the cheek. 

Habitat, Gambia. 



* Lesson, Guerin's Mag. de Zool., 
1839, t. x., Mammiferes. 

t Gray, Ann. and Mag. Nat. Hist., 
1838, vol. i., p. 27 ; Pro. Zool. Soc, 
1867, pp. 272 and 294 ; and Brit. Mus. 



Cat., p. 24. Mr. Elliot, in his Mono- 
graph, identifies this with the species 
last described ; but to me it appears 
very distinct from the latter. 



408 



THE CAT. 



[CHAP. XII. 



(18.) The Servaline Cat (Felis servalina).* 

This animal is apparently of about the same size as F. negkcta, 
but is distinguished from it by its colour, which is yellow, fulvous 
above, and white beneath. The middle of the back is darker, with 
very numerous small black spots, spots on sides rather larger, on 
the belly much larger ; tail short, fulvous, with five or six imperfect 
black rings, and a pale tip. No cheek streaks. 

The type is said to be in the British Museum. 

Habitat, Sierra Leone. 



(19.) The Ocelot (F. pardalis)A 

§ 8. This beautiful cat, always handsomely marked> is either one 
of several closely allied species, or else, as is more probable, is subject 
to much variation as to coloration and the intensity of its markings. 
Besides the typical form, Dr. Gray has distinguished four marked 
varieties (or species) which he has named F. grisea, F. metanura, 
F. picta and F. pardoides, and certainly these forms are not only 
very different when adult, but, as Dr. Gray says, their characters are 
to a certain extent permanent, the young, in some instances at least, 
being like their parents, so that they are at least varieties which 
" breed true." 

The ground colour of the ocelot may be tawny yellow or reddish 
grey. It is always marked with black spots, which are aggregated 
in chain-like streaks and blotches, generally forming elongated spots, 
each with a black border, enclosing an area which is rather darker 
than is the general ground colour. The head and limbs bear small 
black spots, and there are two black stripes over each cheek and one 
or two transverse dark bands within each fore-leg. The tail tends 
to be ringed, and the ventral parts of the trunk and limbs are 
whitish. 

Length from snout to tail-root ranges from twenty-six to thirty- 
three inches ; that of the tail varies from eleven to fifteen inches. 

The pupil contracts into a vertical slit. The orbit is not enclosed 
by bone. 

The creature is a ready climber, and is said to be exceedingly 
bloodthirsty. 

The variety called F. grisea J is of a grey colour, even some- 
what whitish at the sides ; that named F. picta,$ diners from the 
typical F. pardalis in its less intense coloration, the less degree of 
approximation of its stripes and the less amount of difference which 



* Ogilby, Pro. Zool. Soc, 1839, p. 4 ; 
Gray, Pro. Zool. Soc, 1867, p. 395 ; and 
Catalogue of Carnivora of Brit. Mus., 
p. 24; Sclater, Pro. Zool. Soc, 1874, 
p. 495, plate 63. Mr. Elliot identifies 
this in his Monograph with the Serval, 
but in this I cannot at all agree with 
him. 

t Described and figured in Elliot's 



Monograph. He considers the here 
enumerated varieties to be merely 
varieties. See also Godman and Sal- 
vin's Biologia, Mammalia, p. 60. 

X Gray, Ann. and Mag. of Nat. Hist., 
vol. x., p. 260, 1842; and Pro. Zool. 
Soc, 1867, p. 403. 

§ Gray, I. c. 



CHAP. XTL] 



DIFFERENT KINDS OF CATS, 



409 



exists between the general ground colour and the parts enclosed by 
the black borders of the spots and markings. The variety termed 
F. pardoides * is very like the variety F. grisea, but the spots affect 
less the form of rings upon the flanks, while the stripes on the neck 
are less distinct as well as shorter, the ground colour of the neck 
being redder. There are also more or less spots in the middle of 
the back. It differs from the typical F. pardalis by its grey 
colour. 

This greyness in F. pardoides and F. grisea is not the effect of 
age, since it already exists in the kittens. 

F. pardoides measures about twenty-five inches from snout to 
tail-root, and the tail is thirteen inches long. 

Very different from all the foregoing, as well as from the typical 
F. pardalis, is the variety which has been named F. melanura.f Its 
colours are most intense. The ground colour being bright fulvous, 
and the black markings exceedingly numerous and deep, while the 
white parts stand out in strong contrast to the rest. 

The ocelot ranges from Arkansas to Paraguay, and according to 
Mr. Elliot, even to Patagonia. 

Certain other smaller and beautifully-spotted American cats are 
also difficult to distinguish one from another ; but it seems to me 
there are probably three distinct kinds, which are represented in 
our National collection, and are named F. tigrina, F. guigna, and 
F. pardinoides. 

(20.) The Makgay (Fe/is tigrina). X 

The animal thus named must be another very variable species, 
since what I believe to be but different varieties have been de- 
scribed as three distinct species, under the names of F. tigrina, 
F. mitis (the Chati), and F. macroura. 

The F. tigrina of the British Museum, § has rather harsh fur, of a 
dull grizzled colour, varied with black spots and rings. The tail is 
marked with small black spots, often confluent, but not forming 
continuous rings. There are three transverse black stripes on the 
cheek. The head and body together measure a little over twenty- 
four inches, and the tail is about eleven inches long. 

The specimens named F. mitis and F. macroura || have soft, bright, 
fulvous fur, with black spots of variable size, but which are not 
united in chains. The black-bordered patches sometimes have a 
pale centre. 



* Gray, Pro. Zool. Soc, 1867, p. 403. 

+ Pro. Zool. Soc, 1867, pp. 270 and 
403. 

+ See Biologia, Mammals, p. 61. 
Both Messrs. Alston and Elliot have 
agreed in considering that the three 
varieties are merely varieties ; having 
come to this conclusion after together 



examining the fine series of specimens 
in the museum at Paris as well as in the 
British Museum. I adopt their decision, 
though I do not feel sure that the F. 
tigrina and F. mitis of the British 
Museum, mav not be distinct, species. 

§ Gray, Pro. Zool. Soc, 1867, p. 404. 

|| Gray, I. c, p. 271. 



410 



THE CAT. 



[chap, xil 



The length of the head and body is nearly twenty-seven inches, 
that of the tail from fourteen to nineteen inches. 

The animal ranges from Mexico to Paraguay, in warm lowlands 
and well- wooded regions. 

An American variety of cat has been described by Hensel * as 
Felis guttula. The account given, does not make it clear that it 
is a distinct species. The author's description is as follows : — 

" Skull long and narrow, corresponding with that of F. macroura, 
the facial part is smaller compared with the brain-case. Especially 
striking is the height of the skull between the orbits. 

" Ground colour grey yellow ; two dark stripes on the head, 
and a dark stripe from each eye to the forehead ; four stripes, 
tolerably broad, run side by side together on the neck to the 
shoulder. The sides of the neck are furnished with some dark 
marks, and some dark brown or black spots are scattered over the 
whole fur. In the middle of the back (where the ground colour is 
darkest) there are narrow more or less short stripes, which some- 
times run one into the other, forming longer stripes. On the flanks 
the spots are larger and have a lighter centre, which, anteriorly, so 
approaches the ground colour as to change the spots into rings. The 
limbs are much spotted externally. The under parts are lighter (or 
whitish) and less spotted. There is a white spot outside the external 
ear. Tail reaching forwards to the arm, with ten or eleven rings 
and a black tip. Size that of the domestic cat." 

Habitat, South Brazil— Rio Grande do Sul. 



(21.) Geoffroy's Cat {Felis guigna).f 

The F. guigna of the British Museum was described by Dr. Gray J 
by the name Pardalina Warwickii, under the impression that it 
came from India, but was recognized by Dr. Sclater § as being 
the South American Cat described by D'Orbigny.|| The latter 
animal is indeed so like the F. guigna of our National collection that 
I cannot help identifying them as specifically the same, although 
D'Orbigny's animal is not so much spotted. 

It may be described as follows : — 

"Fur short, dusky whitish brown; chin, streak on cheek, and 
throat white; chest and underside paler, black-spotted; crown and 
nape with four, cheek with two, and between the withers one black 
streak ; the four feet and body covered with very numerous, equi- 
distant, nearly equal-sized small black spots ; throat, chest, upper 



* Abhand. Akad. Berlin, 1872, p. 73. 

f Molina, Saggio sulla storia naturale 
del Chili, i. Ausgb., p. 295. See Elliot's 
Monograph, under the name Felis Geof- 
froyi. See also a paper by Dr. Philippi, 
in Wiegniann's Archiv, 1873, p. 8, 
plate 3, where two views of an immature 
skull are given. 



+ Gray, Pro. Zool. Soc., 1867, pp. 267 
and 405, plate 25 ; and Catalogue of 
Carnivora, p. 14. 

§ Pro. Zool. Soc., 1870, p. 706 ; and 
1872, p. 203. 

|| D'Orbigny's Voyage dans l'Amerique 
Meridionale, Mammneres, p. 21, plate 14 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



411 



part of the inside and outside of fore and hind-legs black-banded; 
tail spotted at the lower half, ringed at the end, with a black tip ; 
ears black, with a large white spot." 




Fig. 174.— Skull of Geoffroy's Cat (F. gitigna). 



The skull is very short and broad, and convex above at the muzzle. 
Orbits not completely enclosed ; first upper premolar very small. 
It inhabits Paraguay and Chili. 



(22.) The Ocelot-like Cat (Felis pardinoides)* 

This animal was also first described by Dr. Gray under the mis- 
taken supposition that it came from India. f The type of the 
species came from the Zoological Society's collection, with the re- 
putation of an Indian origin. A second specimen, however, cer- 
tainly received from Bogota, placed its real geographical region 
beyond doubt. It is very like F. guigna, but the spots are much 
larger and in the form of dark blotches, each with a black border. 
The two skins differ somewhat, the type of the species being 
greyer than the skin subsequently received. The skulls also are 
different, but not more so than difference of age may suffice to 
account for, the typical specimen being immature. 

The length of the head and body is about eighteen inches, that 
of the tail being ten inches. 

As has been said, it comes from Bogota. 



* This animal is identified by Mr. 
Elliot with that last described, though 
he allows them to be good "varieties." 



It appears to me that they should pro- 
visionally at least be held as distinct. 
f Pro. Zool. Soc, 1867, p. 400. 



412 



THE CAT 



[CHAP. XII. 



(23.) The Yaguarondi (Felis Yaguarondi)* 

The Yaguarondi is one of the few unspotted cats, like the lion 
and puma. It has a very long tail and a long body, in propor- 
tion to the limbs, and its head is long and low. 

It is of a blackish or brownish grey, with individual variations, 
both greyish and reddish specimens being found in the same 
locality. Each hair being blackish grey at the root, then black 
and greyish again towards the point. 

The female is said to be of a lighter, brighter colour than the 
male. 

The animal is thirty inches from snout to tail, wMle the tail 
is twenty- five inches long. . 

The pupil is said to be round. 

The skull is elongated and somewhat flattened above, but what 
is exceedingly characteristic of the species is the remarkable way 
in which the nose is, as it were, pinched in laterally. 

It inhabits Brazil, Guiana and Paraguay, and North-eastern 
Mexico. 

(24.) The Eyra (Felis Eyra).-\ 

This is the most remarkable of all the cats, from the extreme 




Fig. 175.— The Eyra (Felis Eyra). 



length of its body in comparison to that of its limbs — a condition 
which gives it somewhat the appearance of a large weasel. It is 
also one of the few unspotted cats. 

The fur is soft, of a uniform reddish -yellow or chestnut colour, 

* See Biologia, Mammals, p. 63. t Biologia, Mammals, p. 64. 



chap, xil] DIFFERENT KINDS OF CATS. 413 

with a whitish spot on each side of the upper lip. It is about 
the size of the domestic cat, save that its legs are much shorter 
than that animal's. 

The pupil is round.* 

The skull is much elongated and greatly flattened above. 

The nose is a little pinched in laterally. 

The first upper premolar is present. 

The specimen in the Zoological Gardens was very gentle, but 
another one was quite untameable. 

It inhabits Brazil, Guiana and Paraguay, and though rare north- 
wards of Panama, extends upwards to the Bio del Norte between 
Mexico and Texas. 



(25.) The Colocollo (Felts colocollo) .f 

This animal is about the size of the common cat or somewhat 
larger. It is of a whitish-grey colour, with elongated black marks 
on the back and sides, and with a black mark extending from the 
eye to the jaw. The tail is said to be semi-annulated and the 
lower parts of the limbs to be of a dark grey hue. 

The skull has the orbits not enclosed by bone. 

There is no first upper premolar. The upper true molar is 
visible when the skull is seen in profile. The -infra- orbital fora- 
men is large. The skull is much elongated and depressed. The 
muzzle produced, and the upper surface of the snout markedly 
concave when the skull is looked at in profile. When the skull 
is seen from above, the prominence of the upper jaw causes part 
of the anterior palatine foramina to be distinctly visible. The 
nasals narrow very gradually backwards, and do not extend so far 
backwards as do the nasal processes of the maxillae. 

The animal inhabits Guiana and Chili, and doubtless intermediate 
countries alos. 

(26.) The Busty-spotted Cat (Felts rubiginosa).% 

§ 9. This pretty little cat is said by Mr. Jerdon to frequent 
brush wood and grass growing in the dry beds of tanks, as well 
as the jungle. 

Its colour is greenish- grey, with a faint rufous tinge ; beneath 
and inside of limbs white ; a white superciliary streak extending on 

* This has been kindly ascertained for i mann's Archiv, 1873, vol. L, p. 8, 



me by Mr. A. D. Bartlett, of the Zoolo 
gieal Society. 

t Hamilton Smith in Griffith's Animal 
Kingdom, vol. ii., p. 479 (with a figure) ; 
F. Cuvier's Mammiferes, iii.; F. Strigi- 
lata, Wagner's Supplement to Schreber's 



plate 3, Figs. 1 and 2. 

X See Mr. Elliot's Monograph, from 
which the above figure has been taken. 
It is the F. rubiginosa of Jerdon's Mam- 
mals of British India, p. 108 ; and the 
of Gray, Pro. 



Saugth., vol. ii., p. 546. See also a | Zool. Soc, 1867, p. 269 ; and Catalogue 
paper by Dr. R. A. Philippi, in Wieg- | of Carnivora, p. 18. 



414 



THE CAT. 



[CHAP. XII. 



the side of the nose ; two dark face streaks ; top of head and 
nape with four narrow dark brown stripes, becoming interrupted 
posteriorly, and passing into a series of rusty-coloured marks, which 
on the back, are in the form of streaks, but are roundish on the 
sides of the body. Tail short, more rufous than the body, and 




Fig. 176-— The Rusty-spotted Cat (F rubiginosa). 

uniform in colour, or very indistinctly spotted, the tip not dark ; 
the lower surface and inside of the limbs with large dark brown 
spots ; feet rufous-grey above, black on the soles ; ears small ; 
whiskers long, white ; fur short and very soft. 

It is a very small animal, the length of the head and body 
being Only sixteen or eighteen inches, and that of the tail about 
ten inches. It is a well marked species. 

The skull is elongated, though its facial part is short. The 
orbit is nearly encircled by bone, and the mastoid process is rather 
prominent. The nasal bones are long and narrow, extending 
backwards beyond the adjacent parts of the maxillae. The first 
upper premolar is wanting. 

It is said to inhabit both Madras and Ceylon. 

A cat has been described by M. Alphonse Milne-Edwards under 
the name of F. chinensis, and a similarly named specimen, which 
agrees with the description referred to, is in the National collec- 
tion. The latter is the type of a species named F. chinensis by 
Dr. Gray. 

(27.) The Chinese Cat (Felts chinensis)* 

This animal presents the following characters : — 

General colour pale yellowish grey, interrupted by a multitude 



* Pro. Zool. Soc, 1870, p. 629 ; and 
Catalogue of Carnivora, p. 27. Also A. 



Milne-Edwards, Becherches des Mam- 
miferes, p. 216, plate 31. fig. 2. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



415 



of more or less dark brown spots. Two narrow, elongated white 
marks commence beside the nose and extend on to the forehead, 
and another, in each zygomatic region, extends back on the neck 
beyond the angle of the jaw, with a deep red-brown border above 
and below. Muzzle, lower parts of cheeks and chin white, except 
part of the upper lip, which is yellow and striped. Fine, blackish 
stripes on the head, all but the middle one extending to the begin- 
ning of the back. Chest whitish, with reddish-brown spots, which 
tend to form transverse bands like a series of incomplete collars. The 
spots form elongated markings along the back and sides ; some- 
times the spots of the sides form leopard-like rosettes, but some- 
times they do not do so. 

Length of head and body about twenty-five inches. 

Length of tail, twelve inches. 

The orbits are nearly enclosed by the post-frontal processes. 
The nasals extend backwards about, as far as do the maxillae. 
The first premolar falls early. 

The animal is found near Canton and in Formosa. 



(28.) The Small Cat (Felis minuta).* 

This animal is very like that last described, but it is smaller, and 
the tail is much shorter. The spots also are less rounded and more 
in the form of short stripes. The orbits are nearly enclosed by 
bone, as in F. chinensis, but the nasals extend backwards decidedly 
beyond the hinder ends of the adjacent parts of the maxilla?. 

Length of the head and body, twenty-three inches. 

Length of the tail, six and a half inches. 

This animal inhabits the Indian Archipelago, including Borneo 
and at least the island of Zebu in the Philippine group of islands. 
The F. Herschelii of Grayf appears to be but a light-coloured 
variety of F. minuta. 

(29.) Jerdon's Cat (Felis Jerdoni). J 

This animal is very like F. chinensis and F. minuta, but it is 
smaller, and the spots which mark it are darker and more distinct, 
and they do not so distinctly form stripes on the shoulders. 

The fur is grey, with a few small, distinct black spots. The spots 
on the sides of the body and of the limbs are roundish ; those of 
central part of back are linear and rarely confluent. Tail and feet 



* Gray, Cat. of Carnivora, p. 26. 

+ Pro. Zool. Soc, 1867, p. 401 ; and 
Catalogue, p. 28. 

t The specimen in the British Museum 
which is thus named, was so named 
orally by Mr. Blyth, but was not de- 



scribed till Dr. Gray described it in the 
Pro. Zool. Soc, 1867, p. 401 ; and 
Catalogue, p. 28. Mr. Elliot identifies 
this with his F. rubiginosa, but the two 
appear to me to be distinct. 



416 THE CAT. [chap. xii. 

dark grey brown, scarcely spotted ; chin and under parts, white 
with black spots. 

Length of head and body, seventeen and a half inches. 

Length of tail, five and a half inches. 

(30.) The Javan Cat (Felis javznensis)* 

This form is added doubtfully as a distinct species. It is repre- 
sented in the British Museum by a specimen of small size and of a 
greyish-brown colour with round spots, of a reddish-brown tint, on 
the sides, and with blackish longitudinal streaks along the back. 
There are two stripes on the cheek. Beneath, it is whitish, with 
largish, brown spots. 

Length of the head and body, twenty-two inches. 

Length of the tail, seven and a half inches. 

(31.) The Bushy-tailed Red-spotted Cat (Felis euptihtra)A 

This species was first described by Mr. Elliot from a very imper- 
fect skin, I which is the type of the species, and is preserved in the 
British Museum. There is also there preserved a specimen from 
Shanghae, which closely resembles the skin described by Mr. Elliot 
and is similarly named. 

The following is Mr. Elliot's description : — 

" Ground-colour of the body light brownish-yellow, strongly 
mixed with grey, covered with reddish-brown spots rather oblong in 
shape, darkest and most conspicuous on the hind quarters ; head 
grey, with a white line under the eyes and on the side next to the 
nose; two dark brown stripes on the centre, commencing at the tip 
of the nose, and one on each side, beginning at the eye, pass over the 
top of the head, and down the back of the neck to the shoulders ; a 
dark-red stripe runs from the corner of the eye, across the cheek to 
the base of the ear ; and another, rather lighter in colour, starting 
below the eye, passes across the cheek and curves back under the 
throat. The centre of the back is much darker than the sides, with 
spots of dark brown. Under lip white, as is also the throat and under 
parts. Across the upper part of the breast are four broken bands o{ 
foxy red ; belly covered with large brown spots, becoming rufous 
between the hind legs. Inner side of hind legs buff, with cross bands 
of foxy-red, and covered with small reddish spots to the toes. Tail 
thick, rather short, bushy, darker than the body, with several 
incomplete broken rings of blackish brown. Inside of ear buff, 
behind black." 

Size about that of the common cat. 

The orbits are nearly enclosed by bone. The nasal bones extend 
back decidedly beyond the nasal processes of the maxillse. The 
nasal region is much pinched laterally. There is a small upper front 
premolar. 



•* Gray, Catalogue of Carnivora, p. 
26. 

t Elliot, Pro. Zool. Soc, 1871, p. 760, 



piate 76. It is also described an£ 
figured in his Monograph. 
t No. 52.3.19.1. 



CIIAP. XII.] 



DIFFERENT KINDS OF CATS 



417 



(32.) The Small-eared Cat (Felis microtis)* 

This cat is very like F. chinensis, but differs from it by the small 
size of its ears. The infra-orbital foramen is, moreover, divided. 

The hair is long, soft, and very abundant. The general colour is 
that of F. chinensis, but the spots are redder and more confused ; 
the markings of the zygomatic region are less distinct, as are those on 
the head and neck. The ears have each two white spots behind, 
separated by a vertical blackish-brown band, while in F. chinensis 
the ears are black and have but a single white spot. The tail is 
not distinctly spotted. It inhabits the neighbourhood of Pekin, and 
is also found in Mongolia. 

(33.) The Large-eared Cat (Felts megalotis).\ 

This animal appears to be only known by Midler's description. 
He tells us : — '■ This new species is of the size of Felis minuta ; it 
has, however, much longer and more projecting ears and a much 
larger tail, which is not round but more or less flattened. The 
general colour is yellowish, the back reddish-yellow, and the under 
parts more of an isabella colour The hairs of the head, neck, 
shoulders, hind legs and tail are annulated with black rings, which 
results in giving a marbled appearance to the body There are 
some transverse black stripes on the hind legs, and some reddish- 
yellow and black stripes on the fore legs. The claws are light 
yellow. A dark stripe proceeds from beneath the eyes to the 
ears, where it breaks up into narrower stripes. The hairs of the 
tail are longest at each side, so as to form a lateral fringe, which 
gives the tail its flattened appearance. The tail is partly ringed in 
an indistinct manner. The ears are bluish-white within. The 
iris is orange-yellow, 

(34.) The Flat-headed Cat (Fchs planiceps). \ 

This very peculiar and exceptional cat is one- coloured, with a long 
body and short legs and tail. 

It may be thus described : — 

Fur thick, soft, and long. Top of head dark reddish-brown. 
Two yellow lines extend upwards (one on each side) from between 
the eyes to near the ears ; body dark brown, darkest on the back, 



* Alphonse Milne-Edwards. Eecherches 
p. 221, plates 31a and 316, Fig. 1. See 
also the right-hand figure in Mr. Elliot's 
plate of F. euptilura. Mr. Elliot identi- 
fies this species with his F. euptilura. 
The figures, however, appear to me very- 
different, and I think it best to keep it 
distinct, at least provisionally. 

+ Muller, Ven i and. over de Natuur- 
lijke Geschiedenis Zool., Leyden, 1839- 
1844, Part I. ; Over de Zoogdiernen van 



den Tndischen Archipel., by Salomon 
Muller, p. 54. 

X See Mr. Elliot's Monograph, from 
which the above figure was, by per- 
mission, copied. It is the Viverriceps 
planiceps of Gray, Pro. Zool. Soc, 1867, 
p. 269 ; and Catalogue of Carnivora, 
p. 17. It is the F. plmiiccps of Vigors 
and Horsfield, who first described and 
figured it in the Zoological Journal, 
vol. iii., p. 449, plate 2. 



418 



THE CAT. 



[CHAP. XII. 



every hair tipped with white, a silvery grey appearance being 
thereby given to the cat. Face beneath the eye light reddish, with 
two narrow dark lines across the cheeks to beneath the ears. 
Throat, breast, and belly white, the latter spotted and marked with 
rufous. Inside of legs rufous-brown, growing light towards- 'the 




Fig. 177.— The Flat-headed Cat (F, plan- 



feet. Tail rather short and thickly furred and of a reddish-brown 




Fig. 178 —Skull ov Flat-headed Cat {Felis planiceps) 

colour above, beneath yellowish-brown. It is about the size of a 
domestic cat. 



chap, xii] DIFFERENT KINDS OF CATS. 419 

• 

Length of head and body from twenty-one to twenty- four inches. 

Of tail, from six to eight inches. 

The skull is elongated and the orbits are completely enclosed by 
bone, but its most remarkable character is the large size of the first 
premolars both above and below. The first upper premolar is two- 
rooted and largely developed, its crown being sometimes actually 
longer from above downwards than is the sectorial tooth. The first 
lower premolar is also as vertically extended as is the second. This 
structure would accord with a fish- catching habit, like that which is 
attributed to Felts viverrina. 

Dr. Gray gives Malacca, Sumatra, and Borneo as the habitat of 
this species. 

(35.) The Bornean Bay Cat (Felts Badia)* 

This unspotted and therefore exceptional small species of cat was 
first made known by Dr. Gray from a very imperfect skin (the 
type of the species) which is now in the British Museum. It is 
thus described : — 

" Fur of a bright chestnut colour, rather paler beneath, the 
limbs and the tail being rather paler and redder. The tail is 
elongate, tapering at the end, with a white central streak occupying 
the hinder half of the lower side, gradually becoming wider and of 
a purer white towards the tip, which has a small black spot at its 
upper end. The ears are rounded, covered with short blackish- 
brown fur at the outer side, pale brown within, and with a very 
narrow pale margin. The sides of the upper lip, a small spot on 
the front angle, and the edge of the upper eyelid pale brown. The 
chin, edge of the under jaw, and gullet w 7 hitish." 

The orbits are nearly encircled by bone, and there is a good-sized 
pterygoid fossa. Unlike F. planiceps, this cat has its first upper 
premolar of but small size and with a single root. 

Habitat : Sarawak, Borneo. 

(36.) The Egyptian Cat (Felis caligata). \ 

§ 10. This species varies from pale fulvous, to grey or pale 
yellowish, with darkish transverse markings on the legs and towards 
the end of the tail, and two transverse streaks on the cheeks. 

As has been said in the first chapter, this species is probably the 
main source of the domestic cat. 

According to Dr. Gray, " Many specimens of Felis caligata from 
Africa, like Felis domestica, F. indica, and F. torquata, and many 
other species, have the hinder part of the feet black ; but this is 
not a permanent character; for some of the paler specimens of 
F. caligata have the hind feet paler than the back of the animal, 



* Gray, Pro. Zool. Soc, 1874, p. 322, 
plate 49. 

t Gray, Brit. Mus. Cat., p. 29 ; 



Felis maniculata, E.uppell, Zool. Atlas, 
i., t. 19; Felis Chaus, Riippell, Zool. 
Atlas, i., t. 140. 

£ E 2 



4:20 



THE CAT. 



[CHAP. XII. 



and some of these have the heels more or less brown or blackish on 
the outer edges." 

The tail is long. 

Pale varieties of this cat seem to have been mistakenly described 
as identical with the jungle cat {Felis Chaus) of India, and also with 
the Indian, Felis torquata. 



(37.) The Wild Cat {Felis catus) 
described in the first chapter. 



has been already sufficiently 



(38.) The Indian Wild Cat (Felis torquata). * 

This cat has much resemblance to the European wild cat, but it 
is more fulvous and less striped, and is more slender in its build. 
Length of the body and head from sixteen to eighteen inches. 
Length of tail, ten to eleven inches. 
Habitat : India. 

(39.) The Common Jungle Cat {Felis Chaus) A 

The common jungle-cat is of a yellowish-grey colour, more or less 
dark and unspotted, approaching to rufous on the sides of the neck 
and abdomen, where it unites with the lower parts ; a dark stripe 
extends from the eyes to the muzzle. The ears are slightly tufted, 
rufous black externally, white internally. 

The limbs have two or three dark stripes internally, and they are 
occasionally faintly marked externally also. 

The tail is short, reaching to the heel, and more or less annulated 
with black — most so in the young. 

Length of head and body, twenty- six inches ; of tail, nine to ten 
inches. 

Pupil, oblong erect. 

Skull with the orbits open behind, and with the upper premolar 
distinctly developed. 

This cat ranges all over India, from the Himalayas to Cape 
Comorin and Ceylon, and from the sea level to 8000 feet elevation. 



(40.) The Ornate Jungle Cat {Felis ornata). J 



This cat 



is 



at once well known from all the other Indian 



species by the dimensions of the tail and the small size and equal 
distribution of the spots. In this respect it resembles the Hunting 



* F. Cuvier, Mammiferes ; Felis in- 
conspicua ; Gray, Pro. Zool. Soc, 1867, 
p. 273 ; and Catalogue of Carnivora, 
p. 31. 

t Jerdon, Mammals of India, p. Ill ; 
F. (Lynchnus) erythrotis, Hodgson ; F. 
Jacquemontii, Is. Geoffroy St Hilaire ; 
Chaus Jacquemontii, Gray, Pro. Zool. 
Soc, 1867, p. 275, and Brit. Mus. Cat, 
p. 34 ; Chaus Catalonyx, Gray, Brit. 



Mus. Cat., p. 36. See also Elliot's 
Monograph. 

X Gray, Illustrations of Indian Zoo- 
logy and Pro. Zool. Soc, 1867, p. 401 ; 
Chaus ornatus, Gray, Pro. Zool. Soc., 
1867, p. 275 ; and Brit. Mus. Cat., 
p. 35 ; F. torquata, Jerdon's Mammals 
of Brit. India, p. 110. See also Elliot's 
Monograph. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



421 



Leopard. The tail is somewhat like that of F. Chans. The ears 
are slightly pencilled at the tips. The fur is short and of a pale 
whitish-brown. The spots form transverse bands on the legs. The 
belly has black spots like those of the sides." 

Length of head and body, nineteen inches ; that of tail, eight 
inches. 

The skull has the orbits open behind, and the nasal bones are very 
long and slender. There is a distinct first upper premolar. 

It is said to breed rather freely with Indian domestic cats. * 

Habitat: desert regions of North- western India. 

(41.) The Steppe Cat (Felis candatns) .f 

The following are the characters of this animal : — 

Fur close, sott, pale yellowish, blackish brown at the base, with 
very numerous small irregular spots. The spots are smallest and 
roundest on the dorsal line, oblong on the sides, and forming inter- 
rupted lines on the shoulders and thighs, which are most distinct on 
the outside of the fore-legs, and especially forming four broad cross 
streaks on the front edge of the thighs ; tail cylindrical, reaching to 
the ground, spotted at the upper part of the base, and with eight or 
nine narrow interrupted rings on the upper part of the remaining 
portion, with a black tip. JVose brown, with short hair. Forehead 
and cheeks like the back, but with smaller spots, and without any 
distinct dark streaks from the back edge of the eye. The ears 
ovate, acute, pale brown externally, with a termmal pencil of 
blackish hairs, and whitish on the edge within. Chin, hinder parts 
of the upper lip, under parts of the head, throat, chest, belly, inside 
of legs, and hind feet whitish brown, the chin being whitest and 
the inside of the hind legs and feet darkest. There is a large 
blackish spot on the upper part of the inside of the fore legs, and two 
small cross streaks on the front edge of the inside of the thighs. 
The hinder part of the hind feet to the heel blackish. Length of 
body and head, twenty- three inches and a half; of tail, twelve inches 
and a half ; height of shoulder, twelve inches. 

The orbits are incompletely encircled by bone. There is a small 
anterior upper premolar. The anterior lower premolar is large. 

Habitat : Bokara. 



(42.) Shaw's Cat (Felis Bhawiana). \ 

This cat appears to be distinguished from F. caudafns by its much 
shorter tail; from F. Chans by being spotted throughout, and from 
F. ornata by its short tail, more rufous coloration, and distinct black 



* See Blyth, Pro. Zool. Soc, 1863, 
p. 184. The same is said to be the case 
with F. Chaus and F. rubigwosa. 

t Gray, Pro. Zool. Soc, 1874, p. 31, 



plates 6 and 7, under the name of Chaus 
caudatus. 

X Blandford, Journal Asiatic Society 
of Bengal, vol. xlv., part 2, p. 49. 



422 THE CAT [chap. xii. 

spots on th3 abdomen. It is very different from F. euptilura, 
which has red spots on the sides and rufous bars across the breast. 

Length, from snout to root of tail, twentv-five inches; of tail, 
seven and eight inches. 

The skull is very long. 

General colour pale greyish fulvous above, the back rather 
darker than the sides, underparts white ; the body marked through- 
out with rather small black spots, which are largest on the abdomen, 
smaller and closer together on the shoulders and thighs, tending to 
form cross lines on the latter, and indistinct on the middle of the 
back ; anterior portion of the face and muzzle whitish, cheek 
stripes of rusty-red and black hairs mixed. Ears rather more 
rufous outside, especially towards the tip, which is blackish-brown, 
and pointed, the hairs at the end scarcely lengthened, interior of 
ears white. Taere are some faint rufous spots at the sides of the 
neck. Breast very faintly rufous, with one narrow brownish band 
across. Inner sides of limbs mostly white, a black band inside the 
forearm, and a very black spot behind the tarsus. Apparently 
there are two black bands inside the thigh. Tail dusky above near 
the base, with five or six black bars above on the posterior half, 
none below, the dark bars close together towards the tip. Fur soft, 
moderately long ; the hairs purplish -grey towards the base. Size, 
larger than the common cat, about equal to that of F. Chans. 

Habitat : Eastern Turkestan, Yarkand, and Kashgar. 



(43.) The Manul (Felts Manul)* 

This handsome animal is the wild cat of Thibet, Mongolia, and 
Siberia. It is smaller than the common cat, with very long, soft 
and abundant hair. It is of a pale whitish colour, varied by a 
slight black mark on the upper part of the legs and chest. The 
hairs are yellowish -grey at the base, then yellowish, with their 
points white. There are a few transverse dark bands on the loins, 
which are black, narrow, and rather far apart. A white streak, 
bordered by black above and below, passes obliquely downwards 
and backwards from behind the eye, and there is another black 
mark behind the ear. 

Length from snout to root of tail, twenty-one inches. 

Length of tail, ten inches. 

The skull is remarkable for its breadth and the prominence of 
the interorbital region as compared with the nasal region. The 
nasal bones are very narrow for their hinder two-thirds, and then 
broaden out rather suddenly, forwards. 

Habitat : Thibet to Siberia. 



* Alph. Milne-Edwards, Recher. des I Zool. Soc, 1867, p. 874 ; and Catalogue 
Mazn., p. 225, plate 31c ; Gray, Pro. ' of Carnivora, p. 33. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 




Fig 179. The Manitl (F. ManuTy. 



(44.) The Straw or Pampas Cat (Felis pajeros). * 

This animal is about the size of our wild cat, but is more robust in 
build, with a smaller head and a shorter tail. The hair is long, and 
the colour of the body is yellowish-grey, marked with transverse 
bands of yellow or brown, which run obliquely from the back to the 
flanks. Two patches descend from the eyes over the cheeks, and 
meet beneath the throat- The animal is whitish beneath. The 
legs and tail are marked with dark bands. 

Length from snout to tail root, twenty-five inches ; length of tail, 
twelve inches. 

The skull has the snout remarkably short, and therefore is very 
convex above anteriorly when seen in profile. The nasal region is 
much pinched in laterally, and the nasals are very narrow in their 
hinder half. The zygomata are greatly arched outwards. The first 
upper premolar is wanting. The cusp of the first lower premolar is 
much prolonged. 

This animal appears to be a New- World form which represents as 
it were F. Manul of the Old World. 

It inhabits the Pampas and Patagonia down to the Straits of 
Magellan. 



* Gray, Pro. Zool. Soc, 1867, p. 269 ; 
and Catalogue of Carnivora, p. 18. For 
the skull, see a paper by Dr. R. A. 



Philippi, in Wiegmann's Arcliiv, 1873 
p. 8, plate 3, figs. 3 aud 4. 



424 TEE CAT. [chap. xii. 



(45.) The Northekn Lynx (Felis lyncus). * 

§ 11. The lynxes are animals which present a markedly different 
aspect from that of other cats. Their legs are long and their tail 
is, with one exception (that of the caracal), very short. Their ears 
also are tufted at the tip. The pupil is linear when contracted. 
The orbits are incompletely surrounded by bone. They have no 
tooth representing the common cat's first upper premolar, while 
that answering to its second upper premolar is largely developed. 
The intestines are also very short, f 

The lynxes thus form a little group apart, being structurally more 
separable from the bulk of the cats than are the lion, tiger, jaguar, 
puma, and leopard, which are separable from the mass of feline 
animals as the emphatically " large cats." Still the above given 
characters are variable in the cat group. In some cats, other than 
lynxes, the tail is short, and some have the ears more or less pen- 
cilled. Some, as we have seen, have long legs, and in many the 
first upper premolar is wanting. The lynxes therefore cannot be 
separated off as a nominally distinct group or " genus." 

The lynxes are very variable in their colour and markings, and 
the northern lynx also varies greatly in the abundance of its hair, 
according to the season — the animal having a very different aspect 
in winter from that which it presents in summer. The northern 
lynxes are generally reckoned as forming two species, one belonging 
to the old world, F. borealis, and at least one species belonging to 
the new, F. canadensis. The American forms are also often de- 
scribed as alone constituting three species— namely, F. canadensis, 
F. rufa, and F. maculata. After a careful examination of the rich 
series of skins at the British Museum, I am, however, not only 
quite unable to regard the American varieties as anything more 
than varieties, but I am inclined to the opinion that there can be 
no real specific distinctness between the northern lynxes of the two 
hemispheres — their skulls as well as their skins being so much 
alike. \ 

A. The variety generally distinguished as F. borealis is of a 
reddish- grey colour, sometimes more or less spotted, sometimes very 
distinctly so — especially when young. Its winter dress is more grey 
in colour and is much longer and thicker than its summer coat. 



* De Blainville, Osteog. Felis, plate 3. 

f According to Professor Owen (Trans. 
Zool. Soc, vol. i., p. 131), they are only 
twice the length of the body, beii^ 



X On this question Professor Alphonse 
JVlilne-Edwards has been so obliging as to 
send the following statement of his 
opinion : — " The study of the different 



relatively the shortest intestine known j kinds of lynx is a very difficult study. 

to exist in the Felidce. The hyoid is I "Whether there are several species in the 

connected with the skull by a continuous northern hemisphere, or only races, is a 

chain of bonej, as in the common cat. question which I cannot answer. There 

The ciliary folds of the eye are very long, ! are certainly distinct forms, but before 

and the retina, which is very thin, does j ranking them as species it would be 

not reach the meridian of the eyeball, necessary to determine what variations 

Owen, Anat.of Vertebrates, iii., p. 252. ' are due to climate, season, age, sex, &c." 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



425 



The fur of the cheeks is generally long, so much so as to form a 
pendent thick fringe on each side, but the extent of this develop- 
ment varies greatly. The pads of the feet are more or less over- 
grown with hair. 

It inhabits Northern Scandinavia, Russia, Northern Asia, and 
some of the mountainous districts of Central Europe. One was 
killed at Wurtemberg as late as 1846, and in 1822 one was killed 
in France at St. Julien Chapteril, in the department of the Haute 
Loire. 

This animal is said to attain the length ot fifty inches, but I have 
seen none longer than about forty inches from snout to the root of 
the tail. 

B. The variety known as F. canadensis, is, in colour, very like 
F. boreahs, but all the specimens I have seen are smaller, being about 
thirty inches from snout to tail root, with a tail five inches long. 

C. The variety named F. rufa* is, as its name implies, of a 
reddish colour ; its fur is shorter and less abundant than that of the 
variety named F. canadensis. 




Fig. 180.— The Northern Ltnx, variety F. maculata. 



D. The variety called F. maculata is a very handsome one, its 
fur being ornamented with many spots ; but skins exist which 
present every transitional condition between the long-haired spotted 
form known as F. maculata and the other American forms. This 
variety extends across the North American continent from the Rio 
Grande to Southern California, going at least as far south as 



Biologia Centrali Americana, Mammals, p. 64. 



426 



THE CAT. 



[CHA.P. XII. 



Guanajuato,* and probably extending to near the city of Mexico. 
It is therefore an interesting kind, as being the most southern form of 
Lynx as yet known to exist. The F. metadata figured measures thirty- 
five inches from snout to tail root, and the tail is six inches long. 

(46.) The Parduse Lynx (F. pardina). 

This is the South European lynx. The colour is rufous above, 
white beneath, with numerous rounded black spots over the body, 
the limbs, and the tail. 

It presents no noticeable difference as to size from F. lyncns.f 

At first I was disposed to regard this form as a mere variety of 
the northern lynx (the species thus becoming spotted in southern 
latitudes in the old world, just as it becomes spotted in the 
warmer regions of the new world), but an examination of the skulls 
inclines me to regard F. pardina as a really distinct species. When 
the skull is seen in profile it differs from the skulls of the varieties 
F. borealis, F. canadensis, F. rufa, and F. maculata, in that it appears 
much more raised and convex between the orbits, while the skulls 
of the four just named varieties are relatively flat. The nasals of 
F. pardina extend backwards beyond the nasal processes of the 
maxillae. 

This species is found in Turkey, Greece, Sicily, Sardinia, and 
Spain. In Andalusia it is very often called Gato served, an inter- 
esting indication of the African origin of part of the population/ of 
that Province. 

(47.) The Thibet Lynx {F. isabellina). % 

This form is only ranked as a species provisionally and with 
much doubt. There is in the British Museum the mounted skin ot 
a large lynx, which is uniformly of a very pale isabella colour. 

Length of head and body, forty-one inches. 

Length of tail, seven inches. 

Though so markedly different in colour it may be but a pale 
variety of F. lyncus. § 

(48.) The Caracal (Felis Caracal). \\ 

The caracal is a well-known kind. It is of a slender build, with long 
limbs and with a tail longer than in the other lynxes, reaching down 
to the animal's heels. The ears are three inches long. 

* Biologia, I. c, p. 65. 

t There is a specimen in the British 
Museum which measures forty-one inches 
from snout to tail-root, with a tail seven 
inches long, and which is covered with 
black spots. It is labelled Lyncus lupu- 
linus, and has been described by Dr. 
Gray (Pro. Zool. Soc, 1867, p. 276) as a 
new species. It was brought from the 
museum of the Zoological Society, and is 
represented as having come from Norway. 
But this representation was probably 



erroneous. 

X This is the F. isabellina of Blythe. 
Gray, Pro. Zool. Soc, 1867, p. 276. 

§ Dr. Scully has very kindly shown 
me the skins obtained by him in Central 
Asia, one of which at least is intermediate 
in coloration between F. lyncus and F. 
isabellina. 

|| Jerdon's Mammals of British India, 
p. 113. See also Elliot's Monograph 
and De Blainville's Osteographie, plate 
10. 



chap, xii.] DIFFERENT KINDS OF CATS. 427 

It is of a uniform vinous, or bright fulvous brown colour above, and 
is paler, sometimes almost white, beneath. It is quite or almost entirely 
un spotted, but some obscure spots are visible, in some specimens, on the 
flanks, belly, and inner surface of the limbs. The tail has a black tip. 

The pads of the feet are bald. The skull is rather convex 
between the orbits, as in F. pardina. 

Length of the head and body, twenty-six to thirty inches. 

Length of the tail, nine or ten inches. 

This animal is found in North-western India and in Central India 
to the east coast : also in Thibet, Persia, Arabia, and throughout 
Africa. 

(49.) The Common Cheetah or Hunting Leopard 

(Ct/ncelurus jubata).* 

§ 12. This cat differs much more from all the other cats than any 
other two cats differ one from another, and it therefore may be dis- 
tinguished as constituting a nominally distinct group or "genus." 

It has a short rounded head, with long, slender limbs and a long 
tail. Its ears are rounded, and not at all pencilled: 

It is a large animal, being four and a half feet long in head and 
body, and with a tail two and a half (or two and three-quarters) 
feet long. 

Its colour is bright rufous fawn, powdered with black spots. These 
are not like those of the leopard — arranged in rosettts, nor, as in 
the jaguar, in rings ; neither do they run together into stripes or 
elongated patches, but are distinct, plain, round marks. The tail, 
however, is more or less ringed with black. The hair of the neck 
forms something of a mane, and that of the belly is long and light- 
coloured. 

A black stripe runs downwards from the inner angle of the eye to 
the margin of the upper lip near the angle of the mouth. 

Such are its colour and markings when adult. The young are 
covered with long soft hair of a dark-brown colour, very obscurely 
spotted. The head, the back of the neck, the back, and the upper 
surface of the tail, are pale brown. They have altogether a singularly 
different appearance from the adult. 

The cheetah has the claws always more or less exposed, not being 
completely retractile as in the other cats, though it is furnished with 
the same kinds of ligaments that they have. 

The skull of the cheetah is also very different in shape from the 
skull of every other cat — being very high in proportion to its 
length. The nasals are short, but not so short as in the ounce. 
There is more than one infra- orbital foramen on each side. The 
upper true molar is visible when the skull is seen in profile. The 



* Jerdon's Mammals of India, p. 114 ; 
Gueparda, Gray, Pro. Zool. Soc, 1867, 
p. 396 ; and Cat. Brit. Mus., p. 39 ; De 



Blainville, Osteog., Fclis, plate 4 
(skeleton). 



TEE CAT. 



[CHAP. XII. 



first upper premolar may be present or absent. The second pre- 
molar is very large, projecting downwards as much as does the 
sectorial. 




"$"£""•*:> >y1>«S 






V"**v* JZ 



Fig. 181.— The Cheetah (Cyncehtrus hihata). 



The upper sectorial differs from the corresponding tooth in all 
living cats, in that the inner cusp of that th is so rudimentary as 
to be almost wanting. 




Fig. 182.- The Young Cheetah. 



The os hyoides is connected with the skull by a continuous chain 
of bones — as in the common cat. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



429 



The metacarpals and metatarsals are relatively long. 

The brain is considerably convoluted.* 

The corpus albicans is fairly divided into two corpora mammillaria, 
as in various other large cats. 

The pupil is round when contracted, f 

The animal, as is well known, is employed for the chase, being 
taken to the hunting field in a cart, with a hood over its head. Mr. 
Jerdon has observed it, when let loose after the game, crouch 




Fig. 183. — Skull of the Cheetah (C. julata). 

along the ground, and seek out every inequality of surface to enable 
it to get unseen within proper distance of the antelope it was 
pursuing. Nevertheless it can run with a velocity as great as that 
of a well-mounted huntsman. 

The cheetah is found at least in Western, Central, and part of 
Southern India, also in Syria, Mesopotamia, Persia, and Africa, to 
near the Cape — certainly in both Senegal and Kordofan. 

(50.) The Woolly Cheetah (Cyncelurus lanea)4 

This species has been recently described by Dr. Sclater, and 
appears to me to be distinct, though Mr. Elliot regards it as a mere 
variety of the common cheetah. 



* See Owen, Trans. Zool. Soc. , vol. i. , 
plate 20. 

t Of this I have been made aware 
through the kindness of Mr. A. D. 



Harriett. 

J Pro. Zool. Soc, 1877, p. 532, plate 
55. 



430 THE VAT. [chap. xn. 

It differs from the latter in that it is thicker in the body, and has 
shorter and stouter limbs, and a much thicker tail. Its fur is also 
more woolly and dense, particularly on the ears, mane, and tail. 
The whole of the body is of a pale isabelline colour, rather paler on 
the belly and lower parts, but covered all over, including the belly, 
with roundish, dark, fulvous blotches. There are no traces of the 
black spots which are so conspicuous in the cheetah, nor of the 
characteristic black line between the mouth and the eye.* 

The animal described came from Beaufort West, in Cape Colony. 

§ 13. With the last-named animal closes the list of living cats 
which it is thought may certainly, probably or very possibly, be con- 
sidered as distinct "species." But while doubtless some new species 
may yet be discovered, yet it is, on the other hand, very probable 
that various forms here enumerated as very possibly or probably 
distinct may turn out to be mere varieties. The domestic cat is 
said to breed, in India, with F. Chans and F. rubiginosa, and with 
other species in Ceylon and Africa, and the produce of some of 
these unions may themselves be fertile, and if so, the parents must 
be classed as belonging to one and the same species. 

Casting a retrospective glance over the characters of the species 
described, we see that they differ but in few points. The uniformity 
of their structure, and even of their colour, is very remarkable. Some 
reddish or yellowish shade more or less modified by grey or brown, may 
be said to be their ground tint, marked generally with spots, often with 
stripes more or less black, with the under parts of the body whitish. 
Very generally there are two transverse stripes on the cheeks, and 
bars on the inside of the upper arms, with dark rings round the tail. 
There are no wild kinds of a pure white, nor is there any black or black- 
and-white species, while it is only a few kinds that are of a uniform 
tint and unspotted. The various kinds differ in size, in details of colour, 
in the length of the hair of certain parts, in the length of limbs 
compared with that of the body, and in the length of tail. They 
also differ as to the presence or absence of a tuft of hair on the ear- 
tips, the form of the skull, the enclosure or non- enclosure of the 
orbits by bone, the presence or absence of a first upper premolar, the 
relative size of the first and second premolars, the size of the 
internal cusp of the upper sectorial tooth, the more or less perfect 
retraction of the claws, and the shape of the contracted pupil. 

Besides these characters, certain details of brain -structure, the 
condition of the anterior cornu of the os hyoides, the proximity of 
the stomach to the diaphragm, and the relative length of the 
intestine, are known to be different in different kinds, and no doubt 
various other such divergences exist which have not as yet been 
noted. Indeed, these latter anatomical details have been examined 
in too few forms to enable them to be yet made use of for purposes 
of classification. 

* This line is, however, indicated on one side of the nni2zle of a specimen now 
living in the Zoological Society's Gardens. 



chap, xii.] DIFFERENT KINDS OF CATS. 431 

The living cats being thus uniform in structure, one alone stands 
out as markedly distinct. This is the Cheetah — with its imperfectly- 
retractile claws and rudimentary cusp of the inner upper sectorial 
tooth, its high skull, long limbs and tail, and long metacarpals and 
metatarsals. In it also we saw that the first premolar may be 
present or absent, but that the second premolar is greatly developed 
vertically. Altogether this animal may, as has been said, rank as a 
group or genus by itself, the genus Cyncelurus, of which genus the 
above characters will form the definition. The Lynxes may also, as 
we have seen, be grouped by themselves, but they can hardly be 
reckoned as forming a distinct genus, although their special geo- 
graphical range — being almost entirely creatures of the north 
temperate zone — is a noteworthy character. 

All the other cats, however, must, without question, be included 
in a single genus, Felis. 

It has been proposed to separate off, as a distinct genus, the cats 
with a vertical pupil and an orbit closed behind by bone, and to 
divide the round-pupilled cats into two genera according to the 
presence or absence of a first upper premolar. But these characters 
are too inconstant to serve such a purpose. We have seen that 
in the lion, even the upper true molar may not only be wanting, 
but the skull may show no trace of the tooth's past existence. 
But though the genus Fells must be thus extensive, the kinds con- 
tained within it may, for convenience, be considered as forming 
certain sets, distinguished by trivial marks. Thus the male lion, as 
normally developed, is distinguished from all other cats by its large 
mane, and the tiger by its vertical stripes and large size. A few, 
as the puma, jaguarondi, eyra, F. aurata, F. planiceps, F. badia, 
and F. rutlla, are separable from the rest by their uniform colour, 
but the great bulk of the cats are black-spotted animals A few 
also may be distinguished from the rest as rather "clouded" than 
" spotted." Such are the F. marmorata, F. macrocelis, F. megalotis, 
F. pajeros, F. callgata, F. Mannl, F. neglecta, F. torquata, and 
F. catus. Almost every transition, however, exists between the 
spotted and the clouded cats, and some spotted forms occasionally 
have their spots very slightly marked, so that generic distinctions 
reposing on any such characters would be most futile. 

Fifty species of living cats have been here enumerated as probably 
distinct, but it may turn out that certain of these are mere varieties, 
while some forms here deemed varieties may possibly prove to be 
really distinct species. It is the South American spotted cats — ocelots 
and margays — which are specially difficult thus to determine, and with 
regard to the smaller cats of China, and the adjacent parts of Asia, 
a similar, though perhaps less degree of difficulty occurs. It may 
be that F. Wagati, F. javanensis, F. microtis, and F. Jerdoni, will 
have to be merged in other species. Nevertheless it may be con- 
sidered certain that upwards of forty well-marked species of cats 
now exist. 

§ 14. A much larger number of species have probably existed in 



432 



THE CAT. 



[CHAP. XII. 



the past, most of which have disappeared without leaving any yet 
discovered trace of their existence. Some, however, have left theic 
remains in caves and superficial deposits, while others are made 
known to us by fossil remains. Indeed, a variety of fossil cats 
now extinct have been described, but as to many of them there is 
necessarily great uncertainty, since our. whole knowledge of them 
reposes upon perhaps a lower jaw or one or two teeth. New fossil 
forms are now being so rapidly discovered in North America, that a 
complete enumeration of extinct species* and a correct appreciation ' 
of their affinities must be a work of the more or less remote future. 
From what is already known, there can be no doubt but that 
some cat-like creatures, very different from any now living, once 
existed. 

In the first place, a variety of fossils have been found which 
differ from existing cats in no way that would warrant their being 
placed in any other genus than Felts, Such are cats tbat have 
been found in the newer miocene or oldest pliocene of the Siwalik 
Hills* 

Such, again, are others varying in size from a wild cat to a 
hyaena, which have been found by Professor Gaudryf at Pikermi in 
Greece, and many of those which were before described by Professor 
De Blainville,J and by M. Paul Gervais,§ such as Fells Chrktolii 
(about the size of the Serval). 

The great cat known as the so-called "Cave Lion," Felis 8peJcea,\\ 
which lived in England in middle and late pleistocene times,^[ is a 
well known extinct feline form. 

But besides these fossils, thus referrible to the existing genus, 
there are a variety of other remains which cannot be so referred. 

§ 15. Thus the remains of certain large cats have been found in 
pliocene and miocene, and even in eocene deposits, which differ from 
any existing cats in the enormous size of their upper canine teeth. 
The crowns of these teeth were laterally compressed and trenchant, 
with strong serrations along the margins — a character but feebly 
developed in any of the large living cats. 

Further, the mandible may be widened, from above downwards, 
the better to protect such enormously developed teeth. These tusks 
were indeed so large in some species that the jaws could not be 
opened beyond them so as to allow them to be used for biting. They 
could therefore only have been made use of as daggers, the animal 
striking with them with its mouth closed. Such forms must be grouped 
apart under a distinct generic name — the name Mach^erodus. 
This genus had a very wide range, remains of it having been found 
in Europe, India, and America, both North and South. In some 



* E.g., the Felis cristata of Cautley 
and Falconer. 

t See his "Animaux Fossiles de l'At- 
tique," p. 116, plate 17. 

j Osteographie. Felis. 

§ See his " Paleontologie Frangaise." 



|| Owen, British Fossil Mammals, 
p. 161 ; and "W. Boyd Dawkins in 
Palajont. Society, 1869, cxviii. 

*H As to this and other geological 
terms, see below, Chapter XIV., § 6. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



433 



individuals of this genus, the first inferior premolar may ha\e but 
one root, or may even be wanting altogether, thus carrying the 
reduction of lower teeth to an extreme. In the development of the 
upper canines the Machaerodonts are separated from the general 
condition of the cat tribe, not merely in that they were so immense, 
but that their length necessitated a peculiar mode of use, so that 




Fig. 1S4. — Skull of Mach^rodus smilodon. 

these creatures may be said to have initiated a new and very special 
modification of cat-existence. 

§ 16. Another fossil form of cat has been named Hoplophonetjs * 
by Professor Cope, who represents it as like Machaerodus in having 
the mandible vertically expanded and the upper canines more or less 
largely developed, but as differing from it and from all existing cats 
in that the inferior sectorial has a posterior lobe or "heel/' while 
the superior sectorial has no anterior lobe, such as that which exists 
(Figs. 12 and 46) in all living cats. Its upper molar is largely 
developed (Fig. 185, B) and there is no inferior tubercular molar. 

It is a miocene genus, founded on fossils from the White Rivers of 
Nebraska and Colorado. 



* See Annals and Magazine of Natural 
History for January, 1880, p. 39 ; see 
also Bulletin of the United States Geo- 



logical Survey, 7th Report, p. 509 ; and 
the Proceedings of the Acad, of Nat. Sc. 
of Philadelphia, July 8, 1879. 



434 



THE CAT. 



[CHAP. XII. 



A long known fossil form, Pseud^lurus* (of which several 
species have been described), is from the upper miocene of France 
and North America. 

This animal had an additional lower premolar, so that there were 




s /5 na.fr. size 

Fig 185. 
A Skull of Hoplophoneus oreodontis Cope). B. Grinding surfaces of right upper molar and sectorial. 




y$7nat size. 
Fig. 18G.— Skull of Nimravus brachyops (Cope), from Oregon 

three premolars and one sectorial molar in the lower jaw. The 
lower sectorial has but a rudimentary heel. 



* Gervais, Paleontologie Franchise, 
p. 232 ; see also Leidy's Mammals of 
Nebraska and Dakota in Journal of 
Academy of Natural Sciences of Phila- 
delphia, vol. vii., p. 52, plate 1, fig. 8 ; 



see also Filhol, in Annales des Sciences 
Geologiques, vol. vii., p. 158. The Felis 
quadridentata of De Blainville belongs to 
this genus. 



CHAP. XII. J 



DIFFERENT KINDS OF CATS. 



435 



§ 17. Another miocene form (as large as the jaguar) has also 
been described by Professor Cope, under the name Nimravtjs. It is 
from the vicinity of the White River, Oregon. It is described by its 
discoverer* as having the same form of upper and lower sectorial 
as Hoplophoneus, but as differing from the latter in that it has an 
inferior tubercular molar. The heel to the lower sectorial is large. 
The upper canine is very straight and dagger-like, and the alveolar 
border between it and the second premolar is singularly arched. 

A very interesting form, called Dinictis,! has been found in the 




'7 nat.size . 

Fig. 187.— Skull of Dinictis Cyclops. 



" mauvaise terre " of Nebraska, which is certainly miocene if not, as 
some geologists think, eocene. It was as large as the Northern lynx. 

In this kind the upper sectorial has no anterior lobe, while the 
lower sectorial has a very large bifid posterior lobe or heeiu The 
mandible also is somewhat widened anteriorly ; but the most inte- 
resting character is the presence of a small tubercular molar in the 
lower jaw, together with three premolars in front of the sectorial, so 
that there are three premolars and two molars on each side. 

Another kind has been described by M. Filhol J as Procelurus. 
It has one tubercular molar above and below, with teeth very feline 
in form. The shape of the skull, however, is not feline, and the 
present author is disposed to regard it rather as a creature of the 
weasel kind — an opinion in which he is supported by the concurrence 



* Ann. and Mag. Nat. Hist., I. c, and 
Pro. Acad. Nat. Sc. Philadelphia, I. c. 

f See Leidy's Mammals of Nebraska 
and Dakota, Journal of the Academy of 
Nat. Sc. of Philadelphia, p. 64, plate 5, 
Fig. 1-4. The genus of JSlurogale of Filhol 
seems to be really the same as Dinictis. 



$ See Annales des Sciences Geolo- 
giques, vol. x., p. 192, plate 27, figs. 5, 
6, 8-13, and plate 26, tigs. 2-11 ; and 
in the Bibliotheque de l'Ecole des Hautes 
Etudes, section des Sc. Nat., vol. xix., 
1879, pp. 192-20" 

F F 2 



436 



THE CAT. 



[CHAP. XII. 



of Professor Gaudry. It is only therefore here noticed among cat 
remains.* because Professor Cope appears to regard it as a primaeval 
cat, and it certainly does resemble the cats in the shape of the sectorial 
teeth, the upper one of which has the internal cusp — which, however, 
we have seen to be wanting in the living Cyncelurus. 




10 /21natsize 

Fig. 188.— Skull of Archcelurus debilis (Cope), from Oregon. 



§ 18. A very remarkable miocene fossil, which seems really to have 
been a kind of primaeval cat, is the genus Arcioslurus of Professor 
Cope.f This has the usual number of incisors and canines, but has 
four premolars and a tubercular molar in the upper jaw, and three 
premolars and two molars in the lower jaw. Its feet are very 
slender. 

The single species of the new genus is described as follows : — 
"Mandible, with the anterior face of the symphysis, separated from 
the lateral face by an angle which is not produced downwards. 
Superior sectorial without anterior lobe ; J inferior sectorial with a 
heel. General structure of the jaws, weak; superior canine, small, 
little compressed, with an acute posterior edge which is not serru- 
late ; first premolar in each jaw, one rooted ; second inferior pre- 
molar, large ; sectorials large ; diastemata very short ; alveolar 
border below the inferior sectorial and tubercular teeth everted, 
forming a lar^e osseous callus, which has a free inferior and pos- 
terior margin, the latter rising into the base of the coronoid pro- 
cesses ,° zygomata slender ; post-orbital processes little prominent ; 
front wide^ convex transversely. About the size of the panther." 

This is certainly the most exceptional and uncatlike of all feline 
skulls. 



* It appears to have had an ali- 
sphenoid canal, and M. Filhol regards 
it as perhaps allied to Crrjptoprocta. As 
to these matters, see the chapter on the 
Cat's place in Nature. 



f The American Naturalist for Decem- 
ber, 1879, p. 798a. 

t The upper sectorial appears to me 
however to have a very large, though 
little prominent, anterior lobe. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



437 



§ 19. Yet another miocene genus has been described * by Professor 
Cope. It is named Pogoxodqn, and its skull is about one-sixth, 
smaller than that of the tiger. " The canine is large and compressed, 
as in Machcerodus, and has serrulate anterior and posterior cutting 
edges." The symphysis is much widened to protect the canines. It 
differs from the Macbamodonts in having an additional inferior pre- 
molar tooth. The skull of this animal is singularly elongated, and 
there are three premolars in the lower jaw, while the width of the 




Fig. 189. — Skull of Pogonodon platycopis (Cope), from Oregon. 



diastema between the upper canine and the first premolar (which 
is in place) is such as to seem as if another small premolar may 
have existed. 

A very curious and exceptional eocene form of cat has been 
named Emmilus.f It differs from all other known felines in having 
only four incisors in the lower jaw, and a pair of small canines sepa- 
rated by a very long diastema from the next teeth, which consist 
only of one premolar and one sectorial true moiar. The lower jaw 
is enormously widened towards its symphysis to protect the large 
upper canines. It represents the characters of a flesh-eating, pre- 
dacious animal of the cat-kind, carried out to an extreme degree. 
Professor Cope considers Eusmilus as forming the culminating deve- 
lopment of the Machserodont type of structure (Fig. 190). 

§ 20. A genus named JElurodon, has been founded by Professor 
Leidy $ on an upper sectorial tooth found by Dr. Hayden at the 
Loup River, Nebraska. It closely resembles the corresponding 
tooth of the cheetah in the abortion of the internal cusp. 

A genus termed Limnofeiis has been instituted § to designate 



* See the American Naturalist for 
February, 1880, p. 143, and for Decem- 
ber, 1879, p. 7986. 

+ By M. Gervais in the 2nd part of 
his Zoologie et Paleontologic Generales, 
1876, pp. 53 and 54, plate 12. See also 
Filhol, Becherches sur les Phosphorites 
de Quercy, Ann. des Sc. Geologiques, 
vol. viii., 1877, p. 321, and vol. vii., 1876, 



p. 1 53, plate 28. 

% Journal of the Acad, of Nat. Sc. of 
Philadelphia ; Mammals of Nebraska, 
p. 68, plate 1, figs. 13 and 14. 

§ American Journal of Science and 
Arts, vol. iv., August, 1872. See also 
Silliman's Journal, 3rd series, vol. iv., 
1872, p. 202. 



438 



THE CAT. 



[CHAP. XII 



an extinct form which was as large as the lion. Certain portions of 
the skull and of the mandible, with the lower sectorial, have been 
more or less preserved. The description, however, as yet published 
is too incomplete to admit of its place in the cat series — supposing 
that it really has a place there — being determined. 

The name Trucifelis* has also been imposed on an upper sectorial 
tooth, which is more like a cat's milk sectorial tooth than it is 
like the permanent sectorial. It cannot therefore as yet, any more 
than Limnofelis, be admitted as a recognised extinct member of the 
cat group of animals. 

Our knowledge of the kinds which have been reckoned as distinct 
species (i.e., of the species of the various fossil genera) is too frag- 




Fig. 190.— Part of Lower Jaw and Teeth of Eusmilus Udentatus. 



A. Right side of mandible. 

a. Socket of lower sectorial, 
c Canine, 
i. Incisors. 



B. Under surface of anterior end of 
mandible, 
c. Canine. 
i. The four incisors. 



•mentary to admit of their enumeration, alongside of existing kinds, 
as of equal value. Some four species of Dinidis, five of Psendcelurus, 
three or four of Hoplophoncus, two of Pogonodon and two of Nimravus, 
and at least eleven of Machcerodus have been described. 

It is not possible to arrange the extinct and existing genera in one 
series, but if the cheetah (Ct/ncelurus) and JElurodon be left out, the 
rest may perhaps be arranged on either side of Felis (according to 
their affinities to it and to each other) in the following order : — 

1, Archcelurus. 2, Dinidis. 3, Nimravus. 4, Pseudwlurus. 5, 
Felis. 6, Hoploplioneus. 7, Pogonodon. 8, Machcerodus. 9, Eas- 
milns. 

* By Professor Leidy, I. c, plate 28. 



CHAP. XII.] 



DIFFERENT KINDS OF CATS. 



439 



Of existing cats, it is the clouded tiger (F. macrocelis) which 
most resembles Machcerodus, not only by its very long upper canines, 
but also by the shape «f its skull. Felts planiceps, with its large 
upper premolar, shows a certain affinity towards fossil forms which 
have more developed premolar teeth than have any of the exist- 
ing cats. 

As to the fossil cats, in addition to the structural facts already 
mentioned, it is important to note that Archcehirus, Dinictts, 
Nimravu.% Pogonodon, and Hoplophoneus agree m differing from all 
existing cats (and from other fossil cats,, so far as has been 3^et ascer- 
tained) in that thG carotid and condyloid foramina open separately 
from the foramen lacerum posterius, and in that the ali-sphenoid 
develops a lamina of bone to embrace the external carotid artery, 
the aperture left for the artery forming what is called an ali-sphenoid 
canal* In these respects, however, Machosrodus smilodon resembles 
existing cats. 

It is abundantly evident that the differences between any of the 
species which now live are very small compared with those which 
separate such forms as Archcehirus and Eusmilus from existing 
species or from one another. It is the two last-mentioned genera, 
together with the sabre-toothed Machserodonts, w T hich exhibit to us 
the most extreme and divergent structures as yet discovered, amongst 
those various widely spread, or long existing, forms of animal life 
which can make a valid claim to be considered as belonging to the 
great feline group — to be, in fact, some amongst the various *' kinds 
of cats." 



* These facts are mentioned by Pro- 
fessor Cope (see "American' Naturalist," 
December, 1880, pp. 834 and 835) in a 
paper which has only reached my hands 
as these pages are passing through the 
press. On account of the differences in 
the cranial foramina, Professor Cope 
divides the cats into two families : 
I. Felidse ; II. Nimravidse. But the 
conditions in this respect presented by 
Pseudcelurus and Eusmilus have not yet 
been described. Moreover, while dis- 



posed to admit the claim of Archoelurus 
to rank as a distinct sub-family did it 
stand alone, it seems to me that Dinictis, 
JVimravus, Pogonodon, and Eojrfophonetis 
go far to bridge over the differences 
between it and the other cats, and I 
cannot regard the two last-named genera 
as deserving to be ranked in a sub-family 
distinct from the bulk of the Felidse. 
How exceptional is not Otocyon amongst 
the Canidee ! 



CHAPTER XIII. 



§ 1. Nothing can be understood by itself. All our knowledge 
consists of apprehensions which have been acquired by comparing 
and contrasting one thing with another ; and the more we know of 
any object, the greater is the number of relations we are able to affirm 
to exist between it and other objects. To fully understand any 
living creature, then, we should understand, as far as we can, the 
various relations in which it stands to all other living creatures : 
More than this, we should also understand its relations with that 
part of the creation which is devoid of life — in short, we should 
understand " its place in nature." 

But the reader may deem such an inquiry superfluous as regards 
the animal which we have elected to study ; for any .one who is 
asked, " What is a cat ? " will at once reply " A beast of a certain 
kind which preys on other animals ; " and if again asked " What is 
meant by a beast?" will probably say, "a living four-footed 
animal." If, however, the inquiry be pressed further, and precise 
meanings of " living creature," " animal," " beast," and " beast of 
prey," be demanded, the unsatisfactoriness of mere vague, popular 
conceptions will be plainly shown. We must then endeavour to 
obtain a full, clear, and precise knowledge of what is, or should be, 
meant by the above terms, so that we may be able to answer the 
question, " What is a cat ? " with accuracy, and with a sufficient 
comprehension of the expressions employed in so answering. We 
must know "the why and the wherefore" of the terms of our 
answer. 

§ 2. Now, in the first place, we have seen that the body of the 
cat is bounded on all sides by curved lines and surfaces. Secondly, 
we have recognised that its body consists of different organs and 
tissues, and that wherever we may cut through it, we come upon 
parts which differ one from another — its body, therefore, is anything 
but homogeneous. A third fact about the cat's body concerns its 
chemical composition. We have seen that a great uniformity exists 
in this respect, and that all the main portions of it — its flesh, its 
nerves, its blood, &c. — are reducible to oxygen, hydrogen, carbon, 
and nitrogen, of which (with the addition of a minute quantity of 



chap, xiii.] THE CAT'S PLACE IN NATURE. 441 

a few other elements) the whole cat may he said to consist. We 
have also seen that these chemical elements are built up into 
organic substances of very complex nature (the various albuminous 
substances) which make up its flesh and blood, its nerves, &c. 

So much for facts of structure. As regards function, there are 
several of the cat's activities to which attention must here be 
redirected. The kitten grows, and the adult cat continually uses up 
and replaces, in the wear and tear of life, different parts of its 
substance. Both these kinds of " growth " take place, as we have 
seen, not upon the surface of the body — internal or external — but 
in the very inmost substance or parenchyma of that body, by a 
process of " intussusception. " 

But growth needs the presence of certain conditions without 
which it cannot take place, because life itself cannot be maintained 
without them. The cat, like ourselves, can endure considerable 
changes of temperature, but there are temperatures which it cannot 
long endure and live — such as much below 32° Fahr. on the one 
hand, or near 212° Fahr. on the other. Again, moisture is a 
necessity to it, for a very large part of its body consists of water, and 
in a perfectly dry atmosphere its existence would soon come to an 
end. Besides these conditions, the process of intussusception is not 
only one which the cat can carry on, but one which it must carry on 
if it would continue to exist — the taking in of food is a positive 
necessity for such existence. But this food, as we have seen, is 
partly gaseous, and the animal does not take in one gas at its lungs 
without at the same time giving forth another in its place. There 
is going on, in fact, a process of " gaseous interchange," and without 
the continuance of such a process the cat could not itself continue to 
be. Finally, we have recognised that the cat-life may be described as 
a cycle of changes. Let there be a proper supply of food and good air, 
with sufficient warmth and moisture, and the kitten becomes a cat, 
which again reproduces (the requisite conditions existing) a kitten. 
Every cat, then, possesses an innate tendency to carry on a cycle of 
definite and regular changes when exposed to certain fixed conditions. 

§ 3. In the structural and functional characters above given, 
the cat agrees with all other living creatures, and differs from 
creatures which are devoid of ltfe. All living creatures, not only 
all animals, but all plants down to the lowest fungus or alga, agree 
with the cat in possessing an innate tendency to carry on cyclical 
changes ; the flower becomes a fruit, whence comes a new plant, 
which produces a flower again, and grows by intussusception. All 
need moisture and a certain moderate temperature * for their con- 
tinued existence, and all both feed and carry on a process of gaseous 
exchange with the medium which surrounds them. All consist 
largely of oxygen, hydrogen, carbon, and nitrogen — built up into 
protoplasm — almost all are bounded entirely by curved lines and 

* It is suspected that the germs of I troyed by exposure to a temperature of 
some lowly organisms may fail to be des- I 300° Fahr. 



442 THE CAT. [chap. xm. 

surfaces, and all possess a heterogeneous section, for even the lowest 
animalcule, when cut through, shows that it is composed of a semi- 
fluid substance through which granules are diffused, 

On the other hand, crystals, and many minerals, present a homo- 
geneous surface when cut through, heing perfectly alike throughout 
their entire substance. A few minerals, such as spathic iron and 
dolomite, are, indeed, bounded by curved lines and surfaces ; not 
only, however, can no such character be affirmed of minerals gene- 
rally, but the whole multitude of crystals are actually classified 
according to the angles formed by the plane surfaces which bound 
them on all sides. No such uniformity of chemical composition, 
again, can be affirmed of minerals, as of living* beings, nor are their 
elements built up into protoplasm. It is true that crystals will grow : 
Suspend a small one in a suitable fluid and it will become a large 
one ; break off the angle of a crystal, and, similarly suspended, it 
may replace the part removed by a fresh growth. But such growths 
(unlike those of the cat and of all living creatures) are not brought 
about by internal increase, but by a mere superficial deposit. Many 
mineral substances persist unchanged during variations of tempera- 
ture very far exceeding that between 32° Fahr. and 212° Fahr. 
Many, also, can persist in a perfectly dry atmosphere, since they need 
no moisture whatever. Such processes also as those of food-taking 
and continuous gaseous exchange, are unknown in the non-living, 
inorganic world. Finally, no mineral whatever possesses an innate 
tendency to carry on a cycle of definite and regular changes when 
exposed to any given conditions. A crystal may, indeed, be arti- 
ficially broken up into smaller crystals, which, if suspended, as just 
mentioned, will grow externally, and may be again artificially 
broken up, and so one crystal may be made to produce others. But 
such an action is altogether different from organic reproduction. 
No non-living creature reproduces through an innate power, as 
every living creature does, or tends to do. 

We see, then, what we implicitly affirm w T hen we say that the 
"cat" is *' a living creature," and we may now apprehend certain 
very general and important contrasts which exist between it and 
the whole inorganic or lifeless world. 

§ 4. But an objection may perhaps be made to the above re- 
presentation, as follows : " upon the theory of evolution, living 
beings first arose spontaneously, in a world which, according to the 
view just stated, would be a world devoid of life. But the law of 
continuity forbids the sudden appearance of any phenomenon; 
therefore life must have really somehow existed in such a world, and 
therefore there is no such distinction between the living and non- 
living as that above given." This objection might be re-enforced by 
the following argument: "Your cat gives forth ova and sperma- 
tozoa ; these bodies exhibit such movements and actions as certainly 
imply that they are alive. Yet they do not exhibit the main 
characteristic above given of living things— for they do not tend to 
carry on a cycle of changes wdien exposed to certain fixed conditions. 



chap. xiii. J THE CAT'S PLACE IN NATURE. 443 

Under no circumstances will ova directly reproduce ova, or sperma- 
tozoa, spermatozoa. Such bodies are in this respect like the first living 
creature, which spontaneously arose. At that early period the earth's 
condition was such as to favour spontaneous generation, and there- 
fore no reproductive agency was needed beyond that which naturally 
existed in the matter whence such organisms sprang. They therefore 
neither needed nor possessed reproductive power. Only with the 
fading away of this earlier terrestrial condition were such creatures 
as began to possess a reproductive capacity favoured in the struggle 
for life, and thus by degrees reproductive power became first frequent 
in organisms, then general, and now universal." 

Let us consider first the argument by which the above objection 
has been re -enforced. To it we may reply : Great as is the difference 
between a cat and a cat's ovum or spermatozoon, yet if the whole 
animal series is considered, a variety of forms will be met with 
in which larger and larger portions of what we justly take to be 
true animals are thus detachable and detached. Indeed, at last we 
come to creatures * in whom the cycle of life is, as it w r ere, so split 
up, that it is difficult to say which of the creatures that successively 
appear between one fertilised ovum and another, is to be reckoned 
as the more perfect animal. Yet all these creatures are living, and 
all tend to* carry on a definite and regular cycle of changes when 
exposed to certain fixed conditions. The very same, then, may be 
said of the cat's ovum or spermatozoon. Like the intermediate 
forms of the life cycle of many lowly creatures, the^v also, though 
they do. not themselves tend to " undergo " the whole cycle of changes, 
yet possess an innate power and tendency to initiate, produce, and 
" carry on " that cycle in which they themselves play an important 
part, and by which their own forms are indirectly reproduced. 
Therefore there is no real parity between these elements and 
hypothetical primordial animals, naturally altogether devoid ot 
innate reproductive capacity. No such creatures are known to exist 
now. To believe that such ever existed would therefore (in the 
absence of any positive evidence of their past existence) be at once 
both gratuitous and contrary to experience ; yet experience is the 
admitted source of all our knowledge ! 

Having disposed of the re-enforcing argument, we may now con- 
sider the original objection itself. This objection is the real ground 
upon which a belief in the original existence of non-reproductive living 
beings rests, namely, an a priori necessity reposing on a now pre- 
valent conception as to the " law of continuity." That law, we are 
told, " forbids the appearance of any new phenomenon." We reply 
— so much the worse for that law. The existence of breaks, gaps, 
and new beginnings, is a manifest truth which cannot be denied 
except by playing tricks with language — using words in non-natural 
senses — and by ignoring the differences and paying attention only 
to the resemblances which exist between different things. The 

* E.g., certain jelly-fishes, certain tunicates, and certain worms. 



444 



THE CAT 



[CHAr. XIII. 



foolishness of this kind of reasoning will not really be exaggerated 
if it is represented by an argument such as the following patently 
fallacious one : " A cat is an entity, a dream is an entity, therefore 
a cat is a dream."* 



* This folly is well pointed out by the 
late G. H. Lewes, in the second chapter 
of the second problem of his third series 
of Problems of Life and Mind.' He says : 
' ' Psychol* >gico-metaphysical speculation, 
untrammelled by the distinctions of sen- 
sible experience, easily arrives at Pan- 
psychism. The hypothesis rests upon 
an arbitrary extension of terms, and upon 
an exclusive selection of one order of 
conceptions. By a sufficient elasticity 
of terms we may easily reduce ali diver- 
sities to identity ; all things are alike if 
you disregard their points of unlikeness. 
. . . Stretching terms, it is easy to 
identify life with molecular change, and 
then conclude all things to be living. 
But the biologist must protest against 
such manipulating of conceptions. For 
him life expresses a vast class of pheno- 
mena, never found except in definite 
groups of substances, undergoing definite 
kinds of molecular change. The crystal 
is not alive, because it does not assimi- 
late, reproduce itself, &nd die. . . . Any 
one choosing to stretch terms may say 
that molecules live because molecules 
exist. But in that case we shall have to 
create a now term for the mode of exist- 
ence, which is now called life. . . . 
Playing such tricks with language, we 
may ask : Why should not a lamp-post 
feel and think, since it is subject to 
molecular changes consequent on im- 
pression ? Why should not a crystal 
calculate ? Does not oxygen yearn after 
hydrogen ? Has not hydrogen the pro- 
perty of humidity ? These questions 
seem absurd, yet they are only naked 
presentations of what some philosophers 
have clothed in technical terms, and 
their readers have accepted with con- 
fidence. . . . And why this reliance on 
the law of Continuity ? That law is 
simply a deduction from the conception 
of Quantity, abstracted from Quality by 
mathematical artifice ; it is. one abstract 
idea of existence irrespective of all con- 
crete modes of existence. It has its uses ; 
but note, first, that it is an ideal construc- 
tion, not a real transcription ; secondly, 
that not only is it an ideal construction, 
which once formed becomes a necessity 
of thought, although it is detached from 
and contradictory of real experiences, it 
is also in the very nature of the case only 
applicable to abstract existence ; and not 
to concrete modes of existence. See how 
these considerations nullify the applica- 



tion of the law to the gradations and 
diversities of organic phenomena. If 
Continuity is a necessity of thought, 
not less imperiously is Discontinuity a 
necessity of experience, given in every 
qualitative difference. The manifold of 
sense is not to be gainsaid by a specu- 
lative resolution of all diversities into 
gradations. Experience knows sharply- 
defined differences, which make gaps 
between things. Speculation may ima- 
gine these gaps filled, some unbroken 
continuity of existence linking all things. 
It must imagine this, because it cannot 
imaginethe non-existencecoming between 
discrete existences. . . . Turning from 
the metaphysical to the biological con- 
sideration, it is plain that the charac- 
teristic phenomena observed in organisms 
are not observed in an organisms ; and 
even in cases where a superficial appear- 
ance seems to imply an identity, an in- 
vestigation of the conditions shows this 
not to be so. The actions of a machine 
often resemble certain actions of an 
organism. But when we come to under- 
stand how both are produced, we under- 
stand how the products are really very 
different. We deny that a crystal has 
sensibility ; we deny it on the ground 
that crystals exhibit no more signs of 
sensibility than plants exhibit signs of 
civilization ; and we deny it on the 
gromid that among -the conditions of 
sensibility there are some positively 
known by us, and these are demonstrably 
absent from the crystal. It is in vain to 
say sensibility depends on molecular 
change, therefore all molecular change 
must in some degree be sentient change ; 
we have full evidence that it is only 
special kinds of molecular change that 
exhibit the special signs called sentient ; 
we have as good evidence that only 
special aggregations of molecules are 
vital, and that sensibility never appears 
except in living organisms, disappearing 
with the vital activities, as we have that 
banks and trades' unions are specifically 
human institutions. On the first head ; 
that of evidence, we must therefore pro- 
nounce against the hypothesis of pan- 
psychism. How about its philosophic 
advantages ? To some minds eager for 
unity, and above all charmed by certain 
poetic vistas of a cosmos no longer 
alienated from man, the hypothesis has 
attractions. But while its acceptance 
would introduce great confusion into our 



CHAP. XIII.] 



THE CAT'S PLACE IN NATURE. 



445 



But because the plain evidence of our senses compels us to deny 
that life actually exists or ever did exist in non-living matter, it 
by no means follows that life was not potential/// present in it. But 
" potential existence " is not " an actual existence of a latent kind.'' 
The expression merely means that conditions exist in matter such that 
by the action upon it of influences external to it life will arise within 
it — life not previously present in a latent state, either in the matter 
or in the influences the action of which on matter produces it. Con- 
sequently a belief in such spontaneous generation in no way destroys 
the greatness and sharpness of the distinction which exists and must 
always have existed between the living and non-living worlds. 

§ 5. The contrasts which exist, then, between the cat, considered 
merely * as a livixg being, and the mass of non-living inorganic 
things may be summed up as follows : 

(1) It is bounded by curved lines and surfaces. 

(2^ Its section is heterogeneous. 

(3; It consists almost entirely of oxygen, hydrogen, carbon, and 
nitrogen, and largely of protoplasm. 

(4) It grows by intussusception. 

(5) It needs a certain moderate heat. 

(6) It needs definite supply of moisture. 

(7) It needs food. 

(8) It effects a process of continued gaseous interchange. 

(9) It tends to carry on a cycle of changes when exposed to 

certain fixed conditions. 

§ 6. AYe have next to consider what we imply when w r e say that 
" the cat is an animal." 

Very obvious are the characters which distinguish it from plants 
generally. It is actively locomotive, possesses feelings and in- 
telligence, is of a very different shape, never reproduces by budding, 
and, in feeding, it takes its food into an internal f cavity, its 



conceptions, and necessitate a completely 
new nomenclature to correspond with the 
established conceptions, it would lead 
either to a vague mysticism enveloping 
all things in formless haze, or to a change 
of terms with no alteration in the con- 
ceptions. By speaking of the souls of 
the molecules we may come to talk of 
the molecules as men ' writ small ; ' we 
may assign our controversial passions to 
the torrent, and our dogmatic serenities 
to the summer sky ; we shall see volition 
in the magnet, and contemplative effort 
in morphological changes. If we escape 
this, and regard the life and sentience of 
inorganic bodies as only the lowest and 
simplest stage of consciousness, indis- 
tinguishable from what we now call 
motion except that it has an infinitesimal 
quantity of consciousness ; and if from 
inorganic bodies we pass to simple organ- 
isms, from these to organisms more and 
more complex, the soul enlarging with 
each stage of evolution ; well, then we 



are returned once more to the old point 
of view ; the broad lines of demarcation, 
which our classifications fix, remain un- 
disturbed, and all the modes of existence 
known to science are recognised as such. 
Into this scientific system the meta- 
physical conception of uniform existence 
has obtruded itself and borrowed scientific 
terms ; but the obtrusion is a confusion, 
not an illumination." 

* " Merely as a living being," because 
of course a practically infinite number of 
distinctions exist between such an animal 
as the cat considered by it*e7f, and non- 
living creatures, e.g., no mineral has hair, 
or a brain, &c. 

y A cavity, that is, practically in- 
ternal, for in fact, as we have seen, 
the cat's stomach being but a prolonga- 
tion inwards of its exterior, is " ' morpho- 
logically " outsids the animal. The space 
within each pleura or within the peri- 
toneum is really internal. 



446 THE CAT. [chap. xm. 

stomach, where it is digested. Moreover, if we analyse the cat's 
tissues we shall find they are almost all nitrogenous, such as muscle, 
nerve, and blood, whereas plants, though containing protoplasm, yet 
largely consist of a non-nitrogenous substance termed " cellulose,' ' 
and contain much starch. But we have to seek for distinctions 
between the whole world of plants, and the cat considered merely 
as an animal, and therefore for such distinctions as all other 
animals share with it. Now the above given distinctions as to 
motor power, sensitivity, external form, mode of reproduction, 
manner of feeding, and chemical composition, serve very well to 
distinguish the bulk of animals from the bulk of plants, but when we 
come to examine the most lowly organised plants and animals all 
these distinctions seem to fade away. 

Thus, with respect to motor power, very little difference can be 
perceived between some of the lowest aquatic animals and plants, 
both of which may be compared to a detached fragment of the cat's 
ciliated epithelium, since they consist of a few cells which protrude 
protoplasmic threads, the lowly organism propelling itself about by 
the lashings of such threads. Other animals of considerable com- 
plexity of structure — such as some of the Tunicates — adhere to rocks, 
and appear quite motionless, save when touched, and then they 
eject water from two apertures, thus showing a motor power com- 
parable with that of the squirting cucumber. But there are animals 
still more inert,. such as the bladder- worms, or hydatids, which lie 
hidden in the flesh (or other parts) of the animals they infest, and 
which are little more than small membranous bags enclosing an 
albuminous fluid. On the other hand, various plants show consider- 
able motor power, such as the sensitive plant, Venus's fly-trap, and 
others. 

The last named organism serves to show us also that a high 
degree of impressionability may be present in plants, though we 
have certainly no evidence that any of them possess " feeling." 
But a multitude of the lowest animals seem to exhibit no more signs 
of sensibility than do the lowest plants. The hydatids, just referred 
to, may serve as an extreme instance of such apparent insensibility. 
Hydatids, however, are creatures in an imperfect stage of their 
development, the adult stages of which (tape-worms) do give evidence 
of a power of sensation. So that sensitivity may be potentially 
present in these hydatids as it is in the cat's ovum, which certainly, 
itself, gives no evidence of, nor can be supposed to possess, any 
actual power of feeling. On the other hand, such plant-movements 
as those referred to, are explicable in an altogether different way 
from the sensori-motor movements of animals, while we have no 
ground for attributing to them potential sensibility, since under no 
conditions docs it ever become unequivocally actual. 

As to external form, no distinction can be drawn between some of 
the lowest alga? or fungi on the one hand, and the lowest animals on 
the other, whilst many zoophytes and some other animals, exhibit 
the branching mode of growth common in plants; while some plants, 



chap, xiii.] THE CAT'S PLACE IN NATURE. 447 

as the melon cactus, are not arborescent, but assume a spheroidal 
figure. 

As to modes of reproduction, no absolute distinction can be 
drawn between plants and animals. For many animals reproduce 
by budding (as do zoophytes), and some may even be propagated by 
cuttings. Thus if the Hydra, or the common sea-anemone (Anthea), 
be bisected, each half soon grows into the perfect form once more, 
and many worms (such as Scyllis and Catenula), and animalculae 
called Infusoria, habitually multiply by self-made sections, i.e., by 
spontaneous self-division or " fission " ISTot only, moreover, is 
sexual reproduction as universal amongst plants as amongst animals, 
but even male mobile filaments, closely resembling spermatozoa, are 
developed by very many flowerless plants. 

As to the different modes of feeding practised by plants and 
animals, imbibition is indeed (as has been said) universal with the 
former. But then the digested insects made use of by Drosera and 
Dioncea may be said to be taken into a temporary quasi-cavity, while 
in certain other plants the receptacle has the form of a permanent 
sac. This is the case with the curious pitcher plant {Nepenthes), in 
the pitchers of which insects are caught and decomposed, probably to 
the profit of the plant.* But not all animals take solid food into an 
internal cavity or stomach. Many can only imbibe it through the 
outer surface of their bodies. It is thus that tape-worms (which lie 
perennially bathed in a fluid medium unceasingly nutritious) feed. 

Lastly, we come to the distinction between animals and plants as 
regards their chemical composition. Now it is true that most plants 
are less nitrogenous than are animals. But this cannot be affirmed 
of the great group of Fungi. Moreover, substances which were long 
deemed peculiar to the vegetable kingdom, are now known not to be 
so. Thus, " starch," e.g., has been found even in the human brain ; 
while " cellulose " — the principle of wood — exists in the tough 
external coat which invests the bodies of the Tunicates before 
referred to. 

Thus all the foregoing six distinctions break down with respect to 
a considerable number of animals or plants, though they may serve 
to separate all the higher forms of the two kingdoms of living 
beings. 

Other distinctions, however, exist which have a greater value, and 
may be conjointly made use of in discriminating almost all plants 
from all animals. Of these there are two — the first (A) relates to 
structure ; the second (B) relates to function. 

A. It has been already said that every living organism consists of 
a substance called protoplasm, with which other substances (some 
nitrogenous, some non-nitrogenous) may co-exist. Amongst the 
non-nitrogenous occasional accompaniments of protoplasm is 
" cellulose." 



* The structures referred to are curious pitcher-like productions which are formed 
at the end of foliage leaves. 



448 THE CAT. /chap. xin. 

Now, all plants, except the very lowest, have their constituent 
protoplasm divided into a number of minute separated parts (or 
cells), each such separated part being enclosed within an 
envelope of cellulose. But in no animal whatever does diis 
obtain. 

There are, however, lowly animals .and plants which consist 
each of a single particle of protoplasm, but almost all unicellular 
plants are enclosed within a cellulose envelope — an investment 
which is wanting in such lowly animals. In regard to structure 
then, we have thus an almost complete distinction between all 
animals and almost every single plant. 
B. As regards function, there is a still more important distinction. 
The cat's body is, as we have seen, reducible to a certain 
number of chemical elements. Let a living cat be supplied 
with these same elements, in whatsoever combinations artificially 
produced, and in the greatest abundance, and the animal will 
none the less starve to death, however much it may eat of such 
substances. For the cat possesses no power of building up its 
tissues from inorganic matter, but absolutely needs for its sub- 
sistence a food consisting of organic matter already formed. It 
may be said that such is the case because the cat is a beast of 
prey. But it is the very same thing with the mice, young 
•abbits, or grain-eating birds, on which the cat may live. 
None of these vegetable-feeding creatures can, any more than 
the cat, live upon the inorganic world exclusively. Nor can 
other animals, however lowly, do so, for though a few worms 
have an exceptional power in this respect, yet even they also 
feed, like other animals, upon organic matter. Thus it may be 
affirmed that the cat agrees with every other animal in not being 
able to sustain itself by forming living matter (or protoplasm) 
from the inorganic world alone. With most plants it is far 
otherwise, they can live upon inorganic matter only, and have 
the power of dissolving the carbonic acid of the atmosphere, 
and retaining its carbon while letting its oxygen go free. 
It is by the exercise of this power that all the wood which exists, 
and all coal (which once existed as vegetable substance) have been 
produced. Still, not all plants possess this power ; for the group of 
fungi, together with such parasitic plants as are devoid of green 
foliage leaves, require, as animals do, organic matter for their food, 
and have not the power of thus fixing carbon. 

The cat then, inasmuch as it is an animal at all, differs from 
almost all plants : — 

(1.) In that it needs organic matter for its food, and 
(2.) In that the protoplasm of its body is not enclosed or parti- 
tioned by a structure of cellulose. 
But in that it is not an animal of a lowly kind, it further differs 
from almost all plants : — 

(1.) In its power of locomotion ; 
2.) Its sensitivity ; 



chap. xhi. ] THE CAT'S PLACE IN NATURE. 4A9 

(3.) Its non- arborescent external form ; 

(4.) Its incapacity for reproducing its kind by a process of budding ; 

(5.) Its habit of receiving its food into an internal cavity, and 

(6.) The more nitrogenous nature of most of its tissues. 

As to the points in which the cat resembles plants, it of course 
agrees with them in all those characters by which it is distinguished 
from non-living, inorganic matter. It also further agrees with all 
plant?, and also with all animals, in that at one stage of the cycle of 
life it is represented only by a minute spheroidal mass of protoplasm 
— the ovum or germ. 

§ 7. The cat having been thus compared with the inorganic 
world, and with the world of plants, our next endeavour should be 
to ascertain its position amongst akimals. To be able to do this, 
however, it is necessary to be acquainted with the mode in which 
animals are classified ; for the number of their kinds is so prodigious 
that it would be perfectly impossible to comprehend them without 
the assistance of a well-arranged system of classification — a system 
which may enable the student to conceive of different animals in masses, 
such* masses being arranged in a series of groups, successively smaller 
and more and more subordinate. Animals, like plants, are con- 
sidered as members of one great group, which has been fancifully 
termed a " kingdom " — the animal kingdom containing all animals, 
as the vegetable kingdom contains all plants. The principles adopted 
by both zoologists and botanists in subdividing these "kingdoms" 
are "morphological." By this term it is meant that the characters 
upon which these classifications repose, and by which the various 
subordinate groups are defined, are characters taken from the shape, 
number, structure and mutual relations of the parts of which the 
various creatures so classified are built up, and not upon what such 
parts do — the characters refer to "structure," not to "function." 

The kingdom of animals is divided into a variety of sub-kingdoms, 
each of which is, of course, a very large group of animals indeed. 
Each sub-kingdom is again divided into subordinate groups termed 
classes. Each class is again divided into orders. Each order is 
further subdivided into families ; each family into genera, and each 
genus into species-, while a zoological "'species" maybe provision- 
ally defined as " a group of living organisms which differ only by 
inconstant or sexual characters." Sometimes, when a family contains 
a great many genera which differ one from another in such a way 
that they can be arranged in sets, then the term "sub-family" is 
given to each such set. Similarly, different sets of families may be 
grouped together (it may be only one family in one set and the rest 
in another), and then the term " sub-order " is employed to denote 
each such set of families. Similarly here and there the term " sub- 
class " may be conveniently employed for groups of orders, and 
lastly, sets of classes may sometimes be conveniently united as a 
province. Thus in one sub-kingdom we may merely meet with 
classes, orders, families and genera, while in another we may meet 
with provinces, classes, sub-classes, orders, sub-orders, families, sub- 

g a 



450 THE CAT. [chap. xm. 

families and genera. Each of these groups is in all cases defined (as 
before said) by the common structural characters which the creatures 
included within it possess. The groups become successively smaller 
and smaller (in the number of species they contain) as we descend 
from any sub-kingdom through its classes and orders to its families 
and genera. In other words the groups become successively smaller 
in their extent. In each case the technical name given to a group 
denotes the animals contained within it, and connotes the common 
characters which pertain to the group. Obviously then, the larger 
and more primary the group, the greater the number of kinds 
denoted by it (i.e the greater its extension), and the less the number 
of common characters connoted by it (i.e. the less its intension). 
Obviously also, the ultimate groups, e.g. " species," have the least 
extension, but imply, or connote, the greatest number of common 
characters, i.e. they have the maximum of intension. 

§ 8. Now the animal kingdom (as generally understood) is 
divisible into eight sub-kingdoms, apart from that to which the 
cat belongs. Thus there is the sub-kingdom (I.) Hypozoa, which 
includes all the lowest, so called, animals, such as Amoebae, Fora- 
minifera, Radiolaria and Flagellate animalcules — together forming 
the Bhizopoda — with the lowly parasites called Gregorinida, and 
all Infusoria. (II.) Secondly, there is the sub-kingdom of 
Sponges, Spongida. Next comes (III.) the sub-kingdom which 
includes the Hydra and Sea-anemone, together with all Jelly-fishes, 
Sertularians, coral-animals and such creatures as Beroe and the 
Cestum Veneris. This great sub-kingdom is that of the Ccelentera. 
Then there is (IV ) the sub-kingdom Echinoderma, which includes 
the star-fishes, sea-urchins (or sea- eggs), brittle-stars and the sea- 
cucumbers, some of which are known as the Japanese edible, 
" Trepang." Next (V.) comes the very numerous sub-kingdom of 
Worms, Vermes, amongst which are to be reckoned not only earth- 
worms, leeches, sea-mice and tube-worms — these four forming the 
Annelids — together with tape-worms and thread- worms ; but also 
the flukes (or Trematoda), the Turbellaria, the Bryozoa (or Polyzoa), 
the wheel- animalcules (or Rotifer a), the singularly primitive worm 
Dicyema* together with Balanoglossus (type of the Enteropneusta) 
and the active marine Sagitta, with worms allied to the Echino- 
derma and called Gephyrea. Then we have (VI.) the sub-kingdom 
Arthropoda, largely exceeding, in the number of its species, all 
other sub- kingdoms put together. It includes the crabs, lobsters 
and shrimps, the centipedes and millipedes, the spiders, scorpions, 
tics and mites, and all the vast multitude of Insects. We have also 
(VII.) the sub -kingdom Mollusca, containing all the cuttle-fishes, 
pteropods, snails and whelks, oysters, scallops, &c, with the curious 
lamp-shells. Lastly we have (VIII.) the sub-kingdom Tunicata, 
containing the seemingly senseless forms already noticed as Tunicates, 
with a number of other species ; all of which are often called Ascidians. 

* Described by Prof. E. Van Beneden, . "Recherches sur les Dicyemidse. " It may 
Bull. Acad. Belg. xli., xlii., 1876, | be the type of a distinct sub-kingdom. 



chap, xiil] THE CAT'S PLACE IN NATURE. 451 

Let us now revert for a little time to some of the facts we have 
reviewed as to the cat's structure, selecting certain characters 
(for reasons which will shortly appear,) and viewing them in the 
most general way. We have, in the first place, seen that the cat's 
supreme and governing set of organs, the central part of the nervous 
system, runs along the back of the animal enclosed in a special tube, 
which is separated from the more ventral part of its body by the 
vertebral centra. We have also seen that the central part of its 
circulating system lies above its sternum in the ventral part of its 
body, with the alimentary canal running between it and the spinal 
column. The anterior end of that canal we have also seen to end 
at the mouth, which is placed on the ventral side of the brain. The 
limbs we have noted as consisting of two pairs, neither more nor 
less, each supported by a solid internal skeleton. No prolongation, 
however, of the body cavity or of the alimentary canal enters any of the 
limbs. We have also seen that its blood is red, and that a portion 
of the blood, on its way back to the heart, undergoes a secondary, 
"portal," circulation in the liver. The mouth we have found to be 
bounded by jaws placed one above, the other below — and not laterally, 
or right and left. In development we have recognised that the first 
sign of the embryo is a longitudinal groove, beneath which a 
" chorda dorsalis " is formed, while visceral clefts and arches are 
temporarily developed on each side of the pharynx — the visceral 
arches taking part in the formation of the jaws. The above charac- 
ters are characters all of which the cat shares with a certain number 
of animals not yet here referred to ; namely, with fishes,* frogs, and 
toads, reptiles, birds and beasts, and lastly, with ourselves also. 
These creatures together make up another (the ninth and last,) sub- 
kingdom of animals, the sub-kingdom Vertebrata — so called because 
all the creatures which belong to it possess a spinal column, or 
backbone, made up in most cases (as we have seen it to be in the 
cat) of a chain of spinal bones or vertebrae. The cat then is one 
of the group (Sub-kingdom) of " backboned animals." All these 
vertebrate creatures possess a fundamental agreement in organization 
with the cat, though, as w 7 e shall see, they present various and very 
different degrees of minor structural divergence from it. But the 
creatures which belong to the other eight sub-kingdoms, though they 
greatly vary inter se, yet all agree to differ fundamentally from the 
type of organization presented by the Vertebrata. On this account 
they are often conveniently spoken of as one whole, under the name 
Invertebrata — although they cannot be united into one group by any 
positive characters which are not applicable to all animals whatso- 
ever. That we may be able the better to appreciate, by contrast, 
the value of these vertebrate characters which thus exist in the cat, 
— the presence of which is implied when w ? e say that the cat is a 
backboned animal — it may be well to shortly glance at the organiza- 
tion of one or two of the Invertebrata. 

* There is one fish (the Amphioxus or t ganized than any other vertebrate animals 
lancelet) which is much more lowly or- | — as will be pointed out later on. 

g g 2 



452 THE CAT. [chap. xin. 

Taking then the Lobster as an example of the Art Tiro porta, we 
find it to be a creature the body of which is different indeed from 
that of a beast, bird or fish. Instead of an internal skeleton, we 
find it has a skeleton which is external. Moreover the calcareous 
portions of this external skeleton are moved (as so many levers, one 
upon another) by muscles, as in the cat, but then these muscles do 
not, as in the cat, clothe the skeleton externally, but are enclosed 
within it. Instead of a body the segmentation of which only 
reveals itself internally (by the backbone and ribs), and which is but 
slightly manifested externally (by at most two pairs of serially 
homologous limbs), we find in the lobster a body consisting in great 
part of externally visible segments, which it is plain are serially 
homologous, and which are provided with numerous pairs of limbs, 
which are also serially homologous one with another. Instead of a 
pair of jaws biting vertically, and derived from special modifications 
of the body- wall — i.e., from the visceral arches - — we find a number 
of jaws arranged in pairs and biting laterally, and which are really 
limbs modified in a special manner. Instead of a frame made up 
of two super-imposed cylinders, with the circulating centre ventral 
and the nervous centre dorsal, we find a frame consisting of a single 
cylinder, with the heart placed dorsally and the central part of the 
nervous system extending from before backwards on the ventral 
side of the single cylinder — while there is nothing answering to the 
cat's spinal column. Again, in the lobster the alimentary tube, 
instead of bending away from the nervous centres at its anterior 
end, not only bends towards them, but actually traverses them. 
There are arteries and veins, but there is no portal circulation. The 
organs of sense are also very different from the cat's. The lobster 
has indeed a pair of eyes and also a pair of ears, but these are 
situated on, or in, modified limbs and not in the head, and the eyes 
have not various parts which exist in the cat, while the rods and 
cones of the retina are placed at the surface and not at the deepest 
layer of that membrane. In development, we have no such medul- 
lary groove, becoming a tube, as in the cat (though the nervous 
centres are still formed from epiblast,) nor do visceral clefts or 
arches ever arise ; moreover it is the ventral, not the dorsal, surface 
•of the embryo which first appears. 

As the type of another sub-kingdom, that of the Motlusca, we 
may select the Cuttle-fish, which exhibits a form as different from 
the cat, as is that of the lobster, but also one as different from that 
of the lobster as it is from that of the cat. For the cuttle-fish has 
a large soft body, destitute both of the hard envelope of the lobster 
and of the internal, a«xial and appendicular skeleton of the cat, and 
consisting of a fleshy bag, at one end of which is a head, with a 
pair of large eyes and ten fleshy processes, or " tentacles," radiating 
from the terminal mouth of the bag. The body shows no serial 
segmentation, either externally, as does the lobster, or internally, as 
does the cat, Neither does it show, like both these animals, an 
elongated nervous axis, but instead, certain nervous ganglia (whence 



chap, xiii.] THE CAT'S PLACE IN NATURE. 453 

nerves radiate,) aggregated near the mouth and surrounding the 
alimentary tube. It has eyes, indeed, which are very like the cat's, 
yet the rods and cones of the retina are placed as in the lobster. 
There are no limbs laterally arranged in pairs, as in the cat and 
lobster ; and though it has a pair of jaws, they are no more modi- 
fied limbs — like the lobster's — than they are modified visceral arches 
— like the cat's ; for such arches are not formed in its development, 
any more than are a medullary tube and a notochord. 

The lobster and cuttle-fish are examples of the most highly- 
organized sub -kingdoms which make up the Invertebrata, but some 
species of a sub-kingdom which is in most respects inferior, yet 
present certain noteworthy approximations to cat- structure. The 
sub-kingdom referred to is that of the Tunicata. Some of these 
Ascidians are marine animals, with a leathery coat, or " test," shaped 
somewhat like a bottle with two short necks. Such a creature is 
alike devoid of anything, either in the shape of an external limb or of 
an internal skeleton. Its nervous system consists of little more than a 
ganglion, while (as in a multitude of Invertebrata of different kinds, 
both male and female sexual glands co-exist in each individual. 
Such is its adult condition. Yet during its growth it possesses a 
medullary groove that becomes a dorsal tube developing the nervous 
centres, which are temporarily in the form of an elongated axis ; 
while beneath it a structure is formed which closely resembles the 
chorda dorsalis of the cat's embryo. It is only in some Tunicata, 
however, that this condition temporarily obtains, though in all, the 
nervous centres are dorsal in position and origin. There are no 
visceral clefts and arches as in the embryo cat, yet a number of 
serial openings are formed on each side of the pharynx, which 
persist throughout life, and through which water is propelled by 
the lashings of vibratile cilia. 

All the creatures yet mentioned resemble the cat, inasmuch as 
they exhibit either a serial or a bilateral symmetry, or both. 

But there may be another form of symmetry (entirely absent in 
the cat,) namely, a radial symmetry, which is exhibited by jelly- 
fishes, sea-urchins, star-fishes and others. 

In various Invertebrate sub-kingdoms, various forms of organic 
inferiority are found. Some animals grow up in compound 
aggregations, as do so many of the Cceleiitera. These last-named 
animals have a certain interest for the student of Cat embryology. 
We saw that in the fertilized ovum of the cat, yelk division ended 
in the formation of two layers — one superficial layer of epiblast, 
with a hypoblastic layer beneath it. Amongst the Coelentera we 
find animals whose whole tody, through their whole lives, consists 
only of two corresponding layers : an external layer, the " ecto- 
derm," and an internal layer, the "endoderm;" the endoderm 
(like the embryonic hypoblast of the cat,) lining the alimentary 
cavity. These resemblances are not merely fanciful, for the condi- 
tions, which exist in a multitude of intermediate forms, show that 
there is a real affinity of nature between these corresponding parts 



454 THE CAT. [chap. xiii. 

of these so widely different animals. Amongst the lowest animals 
of all — the Hypozoa — we find conditions which remind us of still 
earlier stages of the cat's existence, and also of fragmentary portions 
of its adult frame. Amongst those lowly parasites the Gregorinida, 
are animals which consist only of a spheroidal particle of protoplasm 
enclosed in a cell-wall and containing a nucleus and nucleolus — quite 
comparable therefore with the cat's ovum. Amongst other lowly 
creatures called Flagellata, some consist of a small spheroidal particle 
of protoplasm, with a filamentary prolongation, or tail, by the 
lashings of which the little creature propels itself along. Such 
organisms are evidently comparable with the c i t's spermatozoa. 
Yet other lowly organisms amongst the Rhizopoda consist of par- 
ticles of protoplasm which slowly change their shape in an altogether 
irregular manner, and which quite resemble the white corpuscles of 
the cat's blood. Such animals are called Amoebce, and it was with 
reference to them that the motion of these blood-corpuscles was 
spoken of as " amoeboid," or " amoebiform." 

But these creatures have a further interest for us. Each Amoeba 
feeds both by imbibing nutritious fluid and by actually engulphing 
within its substance undissolved nutritious particles, and this process 
is comparable with what must take place, in the nutrition of the 
protoplasmic particles which form the ultimate parenchyma of the 
cat's body. Again, each Amoeba effects a gaseous interchange with 
its surrounding medium, gives out carbonic acid and takes in oxygen, 
and this process is directly comparable with that intimate and 
internal process of respiration before described as taking place 
throughout the particles of the cat's parenchyma. Finally, many 
of these lowly animals have the power of secreting within their 
unicellular bodies and extruding from them various formations of 
different kinds, and this process is also comparable with the like 
actions of the epithelial cells which line the ultimate gland-tubules 
of the cat, and also with that universal process of minute and 
ultimate excretion which is carried on by the particles of its ultimate 
body-parenchyma. 

But the whole of the sub-kingdom Hypozoa has also an interesting 
resemblance to the embryonic condition of such an animal as the 
cat at a period anterior to its differentiation into distinct tissues. 
For all the Hypozoa consist either of single cells or of more or less 
simple aggregation of cells, and in no hypozoon are these collected 
and differentiated into tissues — not even into an epiblast and hypo- 
blast — conditions which appear for the first time in the sub-kingdom, 
Sport gida. 

§ 9. Inasmuch, then, as the cat is a backboned animal, it may 
be said to differ from the whole of the Invertebrata in the follow- 
ing points : — 

(1) Its body consists, in the adult as well as in the young con- 
dition, of two unequal antero-posteriorly elongated cylinders 
— one placed dorsally, the other ventrally. 



chap, xiii.] THE CAT'S PLACE IN NATURE. 



455 



(2) The central part of the nervous system is, throughout life, 

an elongated structure in the dorsal cylinder. 

(3) The two cylinders are, throughout life, separated by an 

elongated solid structure — the vertebral bodies or (in the 
foetus) their cartilaginous or soft representative. 

(4) The heart is placed on the ventral side of the thus separated 

off ventral cylinder. 

(5) The anterior end of the alimentary canal bends down away 

from the nervous centres. 

(6) Limbs being present,* they are neither more nor less than four, 

and have an internal skeleton wrapped round by muscles. 

(7) There is a portal circulation. 

(8) Jaws being present, they are formed from visceral arches. 
Were it not for the existence of a very lowly -organised fish, the 

A)7whioxus or lancelet, on the one hand, and of the tunicates above 
referred to on the other, additional distinctive characters to those 
just given could be drawn out. For the lancelet has no distinct 
skull, head, brain, auditory organs, chambered heart, or parts 
formed from visceral arches, such as those we have made acquaintance 
with. The cat then, as a backboned animal, of a type superior to 
the lancelet, differs from all Non- Tunicate Invertebrata, not only in 
the above enumerated characters, but also in that : 

(1) Its body is doubly cylindrical at any time of life ; 

(2) Its nervous centres are an elongated dorsal axis at any time 

of life ; 

(3) It has a vertebral -column ; 

(4) It has a brain enclosed m an anteriorly expanded part of the 

dorsal cylinder, i.e., in a skull ; 

(5) It has mandibular and hyoidean arches ; 

(6) The first sign of the embryo is a medullary groove where the 

nervous centres take origin ; 

(7) Visceral clefts and arches are formed. 

§ 10. Such being the relations borne by the cat as a backboned 
animal to all the creatures which form the Invertebrate sub- 
kingdoms, the next point to examine is its relations to its fellow 
Yertebrates. 

Now the sub-kingdom Vertebrata consists of three provinces and 
five classes as follows : — 

It consists of the province ZYGENCEPHALA,f containing one class 
only, the class Mammalia, which is the class to which all beasts, in- 
cluding of course the cat, belong, and of which man also (zoologically 
considered) is a member. The province Monocondyla % contains 
two classes : the class Aves (birds), and the class Reptilia. The latter 



* This mode of expression is used 
because many back-boned animals have 
no limbs, and we are here considering 
only such characters in the cat as are 
common to every back-boned animal. 

f A term referring to the median 



union of the cerebral hemispheres by a 
corpus callosum. 

± A term referring to the union of the 
skull and spine by one occipital condyle 
only. 



c 



456 THE CAT. [chap. xiii. 

class embraces all crocodiles, lizards, serpents, and tortoises, with 
extinct forms more or less allied to these The province Branchiata* 
is the third and last. It consists of two classes : the class Batra- 
chia — i.e., the class of frogs, toads, efts, and their allies — and the 
lass Pisces, which includes all fishes. 

Our present task, then, is to see what is implied in saying that 
the cat is a " beast " or a " mammal." To see this we must know 
its relations, simply as a mammal, to the other forms of vertebrate 
life, i.e., to the groups Pisces, Batrachia, Branchiata, Reptilia, 
Aves, and Monocondyla, and to all the non-mammalian vertebrates 
taken together. 

If, to help us in our comparisons, we examine any ordinary fish, 
such as the cod (Gadas), we see in it an animal with a large, neckless 
head and a long and powerful tail, with a membranous production 
from the back (a dorsal fin), one beneath the tail (an anal fin), and 
two pairs of fins placed laterally, ventrally and far forwards, and 
termed respectively the pectoral and ventral fins. The body of the 
fish is clothed with scales, and exhibits an undulating mark running 
from before backwards (from head to tail) on each side, called the 
lateral line. The tail ends in a membranous, vertical expansion, or 
caudal fin, which is supported (as are all the other fins) by many 
delicate but firm fibres within its substance, called fin-rays. The 
nostrils do not open into the mouth posteriorly, but each has two 
openings on the exterior of the snout. The orbits do not com- 
municate with the nares by any lachrymal tube, nor the ears with 
the mouth by any Eustachian tube, but there is a large aperture on 
each side behind the head, which leads into a chamber wherein are ' 
a number of membranous plates, or " gills," attached to the outside 
of a series of arches between which are clefts leading into the 
alimentary canal just behind the mouth. These gills are breathing 
organs, adapted to aid the needful respiratory gaseous exchange 
between the blood within them and the atmospheric air which is 
dissolved in the water the animal inhabits. There is a perfectly- 
closed air-bladder just beneath the vertebral column, but there are 
no lungs and no pulmonary arteries. The aorta divides — as in the 
embryo cat — into a series of arches which ascend the sides of the 
pharynx to reach the dorsal aorta, but each artery is, on its way 
upwards, broken up into a network of minute capillary vessels 
within the membranes or leaflets of the gills. Thus the blood leaves 
the heart in an impure or venous condition, and, having gone thence 
to the aquatic respiratory organs — or gills — it does not return directly 
to the heart, but passes up in an arterial condition to the dorsal 
aorta. Consequently neither a second auricle nor a second ventricle 
is required, and neither exists — the heart consisting, as in the 
embryo cat, only of a single auricle and ventricle, the venous blood 
passing into the former from a " sinus venosus," and being given 

* A term referring to the all but uni- I life if not permanently) in all Batrachians 
versal presence of gills (at one time of ' and Fishes. 



chap, xiii.] THE CAT'S PLACE IN NATURE. 457 

out by the latter into a "bulbus aortaD," whence the lateral aortic 
arches take their origin. Other transitory conditions of the cat's 
embryonic circulation are found persistent in the cod. Thus the 
blood is brought back to the heart by large anterior and posterior 
cardinal veins which unite on each side in a " ductus Cuvieri," which 
opens into the sinus venosus, and no large iliac arteries, or great 
anterior and posterior venae cava? are ever developed. Similarly in 
the development of the cod, no umbilical veins or arteries ever 
appear, for no allantois (and indeed no amnion) is ever formed ; but 
the omphalo-meseraic arteries and veins are the only ones employed 
in nourishing the embryo. But the nature of the arches which 
support the gills needs explanation. 

We have seen how, in the cat, the hard parts of the successive 
visceral arches of the embryo respectively become the mandible, the 
chain of bones forming the anterior cornu of the os hyoides, and also 
its posterior cornu or thyro-hyal.* In the cod, similar arches also 
become (successively from before backwards), the mandible and the 
chain of bones answering to those of the cat's anterior hyoidean 
cornu. But the visceral arches more posteriorly placed, become 
these successive arches which (because they support the gills) are 
called " branchial " — one branchial arch being formed from each 
such more posteriorly-situated visceral arch. All the gill-arches of 
each side answer, in fact, to one of the cat's thyro-hyals, as we 
shall see more distinctly in considering Batrachians. 

The two pairs of lateral fins before noticed — the pectoral and 
ventral fins — answer to the pectoral and pelvic pairs of limbs of the 
cat, but their internal skeleton is not divisible into arm, carpus, and 
digits ; or leg, tarsus and digits — that is to say, they have not what 
we may call the " typical differentiation." f The muscles of the 
limbs are few in number and simple in arrangement. The ventral 
fins are attached to two bones which answer to the cafs pelvis, but 
they are so far from forming a "limb-girdle " that they do not even 
tend to reach the axial skeleton. The "shoulder-girdle," however, 
is well developed, and, though there is no sternum, it is complete in 
the middle line below, while above it is continued on by bones till it 
abuts against the skull. 

The lower jaw consists of more than one bone on each side, and is 
attached to the skull by the intervention of a complex, bony, and 
cartilaginous structure, which may be shortly spoken of as a 
smpensonum. Into its composition parts enter which correspond 
to the auditory ossicles- of the cat. On the base of the skull is a 
large, long bone called the parasphenoid (which is not represented in 
the cat's skull, save by membrane on the basis cranii), but there is no 
basi-sphenoid and the periotic bones (i.e., the pro, epi and opisthotics) 
remain as distinct, permanently, as they temporarily do in the 
embrvo cat. They do not, therefore, coalesce to form a "petrous 
bone." 

* See ante, p. 339 I vertebrates which have limbs and which 

f So called because it exists in all > are not fishes. 



458 



TEE CAT. 



[chap, xiil 



The brain has very small cerebral hemispheres unconnected by 
any corpus callosum, and the optic lobes are relatively very large, 
thus agreeing with the brain of the embryonic cat. There are 
no hypoglossal nerves, and the olfactory nerves do not traverse 
any cribriform plate, nor has the ear any tympanic membrane, spiral 
cochlea or fenestra ovalis. There are no Fallopian tubes, and the 
ovaries in the female are (as well as the testes in the male) directly 
continuous with ducts which lead to the exterior. There is no cloaca 
and there is no penis, but the anal, urinary, and sexual apertures all 
open on the surface of the body, the anal opening being in front and 
the urinary opening the most posteriorly situated. No temporary 
urinary organs are developed to be replaced by true kidneys, but the 
primitive urinary organs persist. The blood is cold, and its red cor- 
puscles are nucleated. There being no lungs and no trachea, there 
is of course no larynx. Similarly there is no diaphragm, such as 
we have met with in the cat. 

Fishes, generally, agree with the cod in the above-mentioned 
characters, but some exceptions should be noted. The lowly orga- 
nization of the lancelet has been already referred to. Amongst the 
highest fishes, such as the sharks and rays, the skeleton is cartila- 
ginous ; there is a cloaca, and there are Fallopian tubes.. In the 
very exceptional mud-fish (Lepidosiren) the heart has two auricles, 
the nostrils open posteriorly within the front of the mouth, and 
there are lungs and a pulmonic circulation- 

§ 11. The cat then, inasmuch as it is a mammal, may be said to 
differ from the class of Fishes in the following points : — 

(1) It has a skeleton, the appendicular parts of which have the 

typical differentiation, 

(2) The hyoid is a structure with simple thyro-hyals, which are 

not in the form of successive arches. 

(3) The skull has a large basi-sphenoid, without any para- 

sphenoid. 

(4) It has a petrous bone. 

(5) Its mandible consists of two bones only — one on each side. 

(6) The mandible directly articulates with the skull, and there 

is no suspensorium. 

(7) The auditory ossicles are minute, and take no share in sus- 

pending the mandibles to the skull. 

(8) There are cervical vertebrse. 

(9) Its ribs join a sternum. 

(10) Having pelvic limbs,* its pelvis is united dorsally to a 

sacrum. 

(11) The body is furnished with hair. 

(12) The muscles of its limbs are complex, f 



* This expression is adopted because 
in some mammals which have no pelvic 
limbs there is no junction of pelvis and 
sacrum. 



1* Even in mammals such as the por- 
poise, in which the limbs are mere pad- 
dles, the muscles are very different from 
those of the cod. 



chap, xiil] THE CAT'S PLACE IN NATURE. 459 

(13) Its cerebral hemispheres are large, and united by a corpus 

callosum. 

(14) There are small corpora quadrigemina instead of large optic 

lobes. 

(15) There are hypoglossal nerves which perforate the exoc- 

cipitals. 

(16) The olfactory nerves being present,* traverse a cribriform 

plate. 

(17) The ear has a tympanic membrane and an Eustachian tube. 

(18) The posterior nares open far back within the mouth.f 

(19) There are no gills at any time of life. 

(20) Respiration after birth, is pulmonary only. 

(21) The heart consists of two auricles and two ventricles. 

(22) All the blood of the body traverses the lungs. 

(23) There is but one aortic arch. 

(24) There is a large anterior vena cava and a large posterior 

vena cava. 

(25) There is a larynx. 

(26) The hinder end of the alimentary canal does not terminate 

anteriorly to the urinary outlet. 

(27) There is a complete diaphragm aiding respiration. 

(28) There are no fin rays. 

(29) The red blood-corpuscles are not nucleated, and the blood is 

warm. 

(30) There are cervical vertebrae. 

(31) In development an amnion is formed. 

(32) Cardinal veins, at first important, afterwards become subor- 

dinate to the venae cavae. 

(33) Kidneys replace transitory Wolffian bodies. 

(34) There is an allantoic placenta.^ 

(35) There is a fenestra ovalis. 

§ 12. We come now to the class Batrachia, which contains, be- 
sides the frogs, toads, and commoner efts, certain noteworthy eft-like 
creatures, such as the gigantic salamander of Japan and China, the 
Afenopoma, Ampfiiuma, Menobranchus and Siren of the United States, 
the Axolotl of Mexico, and the Proteus of the dark subterranean 
caverns of Carniola and Istria. Besides these animals, the class also 
contains certain limbless creatures which look like something between 
snakes and earthworms. They have long, slender bodies, marked by 
many transverse wrinkles, and are called Ophiomorpha. Creatures 
which lived during the deposition of the carboniferous strata, and which 
are known as Labt/rinthodonta, are also included amongst Batrachians. 
The common frog (Rana temporaria) may be taken as a type of this 
class. This animal has two pairs of well but unequally developed 



* In a few mammals they are absent. 

+ That they open into the mouth at 
all, would serve to distinguish the cat's 
class from all fishes save such as the 
Lepidosiren. 



X In certain sharks a placenta is 
formed, but by the intervention of the 
umbilical vesicle. It is not therefore an 
allantoic placenta. 



460 THE CAT. [chap. xin. 

limbs, eacli of which ends in four or five digits, and has the typical 
difterentiation. Though without a neck externally visible, it may 
be reckoned as having one cervical vertebra. Its body is not only 
devoid of hair, but also of scales, and is perfectly naked and more 
or less moist — its surface helping importantly in the respiratory 
process. The adult has no fins, but in the young, or tadpole con- 
dition, fins are present, but are always devoid of fin rays. Neither 
is there any lateral line. The nostrils open within the mouth, and 
the tympanic cavity communicates with the throat by a wide and 
short Eustachian canal. In the adult, there are no gills, but 
there are lungs with pulmonary arteries and veins and two auricles. 
Nevertheless not all the blood goes through the lungs at each 
circuit ; and there are several aortic arches. In the young there is 
but one auricle, and there are gills and an arrangement of vessels 
substantially as in the cod. Similarly in the young there are gill 
arches behind the hyoidean cornua, which latter answer to the 
anterior hyoidean cornua of the cat. In the course of deve- 
lopment, however, these hinder gill arches shrivel into what 
evidently represents the thyro-hyals of the cat. The blood has its 
red corpuscles nucleated, and the cardinal veins of the young become 
subordinate to the subsequently developed vense cavae. The pelvic 
limbs are attached to a pelvic girdle which joins a sacrum, but no 
ribs articulate with the sternum. The muscles of the limbs are 
numerous and complex. The skull has a large parasphenoid, but 
no basi-sphenoid. The periotic bones coalesce. The cranium joins 
the spine by two occipital condyles, but the basi- occipital is rudi- 
mentary. The mandible consists of more than two bones, and it is 
suspended to the skull by a complex suspensorium, including parts 
representing the auditory ossicles. The same may be said of its 
brain as has been said of the cod's. The olfactory nerves traverse 
no cribriform plate, but there is a well-developed tympanum, though 
there is no spiral cochlea. The alimentary canal and renal and 
sexual ducts open into a common cloaca, and the primitive urinary 
organs persist. Respiration, though serial, is not effected by a 
diaphragm, but the lungs open into the alimentary canal by a short 
tube, at the anterior end of which is a simple larynx. 

§ 13. Bearing in mind the conditions presented by the other forms 
of the class Batrachia, we may say that the cat, as a mammal, differs 
from all Batrachians, as follows : — 

(1) Its skull has a large parasphenoid, but no presphenoid. 

(2) Its mandible consists of two bones only, one on each side. 

(3) Its mandible directly articulates with the skull, and there is 

no suspensorium. 

(4) Its auditory ossicles are minute, and take no share in sus- 

pending the mandible of the skull. 

(5) Its ribs join a sternum. 

(6) Its body is furnished with hair. 

(7) Its cerebral hemispheres are large and united by a corpus 

callosum. 



chap, xiii.] THE CAT'S PLACE IN NATURE. 461 

(8) It has small corpora quadrigemina instead of large optic 

lobes. 

(9) Olfactory nerves being present, tbey traverse a cribriform 

plate. 

(10) The posterior nares open far back within the mouth. 

(11) There are no gills at any time of life.* 

(12) Respiration is pulmonary only from birth. 

(13) Its heart is furnished with two ventricles. 

(14) All the blood of its body traverses the lungs. 

(15) It has but one aortic arch. 

(16) There is a complete diaphragm aiding respiration. 

(17) Its red blood-corpuscles are not nucleated, and its blood is 

warm. 

(18) There are several cervical vertebrae. 

(19) In development an amnion is formed. 

(20) Kidneys replace transitory Wolffian bodies. 

All these characters serve to distinguish the Cat's class from that of 
Fishes, as well as from Batrachians, and therefore they will also 
serve to distinguish the cat, in so far as it is a mammal, from the 
whole province Bkanchiata. 

§ 14. From amongst the creatures included in the classREPTiLiA (the 
lower of the two classes which make up the province Monocondyld) 
we may select, as a type, the common lizard (Lacerta agilis). In it 
we find a little long-tailed quadruped, the body of which is clothed 
with horny epidermal scales. The thoracic and abdominal portions 
of its body-cavity are not divided by a diaphragm, for it — unlike 
that of the cat — forms no complete partition. The ribs are connected 
with a sternum. The skull has but one occipital condyle. The 
mandible consists of more than one bone on each side, but is con- 
nected with the skull by one bone only — the os quadratum. This 
bone answers to the proximal part of the cat's malleus, while the 
part of the mandible which articulates with it answers (as it does 
also in the Branchiata) to the distal part of the malleus. There is 
no cribriform plate. The periotic bones unite with adjacent skull 
bones before uniting with each other, so that they do not form a 
" petrous bone." The limbs have the typical differentiation, and 
the pelvis joins the sacrum. But the joint of the hind foot with 
the leg, is not situated between the tarsus, as a whole, and the tibia, 
as is the case in the cat. It is situated in the middle of the tarsus, 
the proximal part of which is firmly bound to the tibia by fibrous 
tissue, while the distal part of it is similarly bound to the meta- 
tarsus. The phalanges of the digits are more numerous than in the 
cat, and differ in number in different digits. There is no corpus cal- 
losum, but there are a pair of large optic lobes. The lungs are freely 
suspended in the thoracic cavity, but the bronchi do not branch 
within them dichotomously. The two ventricles of the heart are 

* This and the next character do not i pipa toad, and of one or two other kinds, 
apply in every case, as the young of the | seem never to develop gills. 



462 THE CAT. [chap. xiii. 

but incompletely divided, and the posterior nares open far forwards 
within the mouth. There are Fallopian tubes, and in development 
both an amnion and allantois are formed, but no placenta — the 
allantois being itself directly respiratory. There are never any 
gills. 

Some lizards and almost all serpents are limbless, but the croco- 
diles and alligators differ from the other reptiles in having two 
distinct ventricles, with nares prolonged to quite the posterior end of 
the palate. Nevertheless, even in crocodiles, there is more than one 
aortic arch, and these arches so communicate that a mixture of 
venous and arterial blood takes place in them. 

§ 15. We may then say that the cat, as a mammal, differs from 
the whole class Reptilia in the following characters : — 

(1) There is a petrous bone, and a mandible formed of two bones 

only, each directly suspended from the squamosal. 

(2) The auditory ossicles are minute, and take no part in sus- 

pending the mandible. 

(3) There are two occipital condyles. 

(4) The skin is furnished with hair. 

(5) There is a corpus callosum, and the corpora quadrigemina 

are small. 

(6) There is a cribriform plate. 

(7) All the blood passes through the lungs at each circuit. 

(8) There is no communication between the arterial and venous 

vessels outside the heart, save the capillaries. 

(9) There is but one aortic arch. 

(10) There is a complete diaphragmatic partition. 

(11) There is no intertarsal joint, the tarsus moving as one whole 

upon the tibia. 

(12) The red blood corpuscles are not nucleated, and the blood is 

warm. 
With the exception of the crocodiles and alligators, we may say 
that the cat also differs from all reptiles :— 

(13) In that it has two distinct ventricles, and 

(14) In that the posterior nares open far back within the mouth. 
§ 16. Turning now to the class Ayes, whatever bird we may 

select as our type, will exhibit to us structural peculiarities well 
deserving attention. The rook (Corvus) will be a good example to 
contrast with the cat and the cat's class. Its different external 
aspect (as compared with the cat) depends upon the following con- 
ditions : — The rook's posture, on the ground, is nearly upright, its 
body being supported on the legs only, the pectoral limbs being 
modified into wings. The facial part of the head is produced into a 
long, conical, pointed beak. The region of the chest is rounded and 
prominent. The whole frame (except the beak and legs) is clothed 
with feathers, and it is to them that the appearance of a long tail 
is due, for only a stumpy tail- structure is visible when they are 
removed. The feathers are v<ery different in different parts of the 
body, much the longest being attached to the tail and arm, and 



chap, xiii.] TEE CAT'S PLAGE IN NATURE. 463 

especially to tlie distal segment of the arm, which corresponds to 
the fore-paw of the cat. The lower parts of the legs are clothed 
with homy scales. 

In internal structure, the main characters agree with those of the 
cat, but there are a multitude of differences. The more significant 
of these are as follows : — The thoracic and abdominal cavities are 
not quite separate, the diaphragm forming only an incomplete 
partition . 

The cervical vertebrae are thirteen and the dorsal eight, and 
behind these no less than ten, at the least, are fused with the pelvis 
into a great solid sacral mass which includes even the last two 
dorsals. The caudal vertebrae are few and end in a bone, shaped 
somewhat like a ploughshare, called the zygostyle. 

The ribs which are connected with the sternum are connected 
with it, not by the intervention of costal cartilages, but by long 
narrow bones (sternal ribs) instead. 

The sternum consists mainly of a great flattened quadrangular 
sheet of bone, from the middle of the ventral surface of which a 
long and strong keel projects, supporting a mass of flesh which lies 
on each side of it, and which is related to the power of flight. 

The skull has but one occipital condyle, and the front apertures 
of the nares are placed some distance back from the front end of the 
skull — one on each side of the bony beak. No zygoma passes back 
from the hinder margin of the orbit, but a needle-like bone bounds 
the orbit externally below, passing backwards from the beak to 
abut against a movable complexly shaped bone — the os quadratum. 
Inside the skull there is no cribriform plate, but only a foramen for 
the nerves of smell, while the bony palate shows some large open- 
ings, two of these being the posterior nares. The periotic bones 
unite with other cranial elements before uniting together. 

The lower jaw, toothless like the upper, is made up of several 
bones on each side. It does not join the squamosal, but fits, by an 
irregularly shaped hollow cup, to the lower part of the os qua- 
dratum. 

The shoulder-girdle is complete. Instead of each blade-bone 
having only a small coracoid process, there is, as in the lizard, a 
large and distinct coracoid-bone, which passes down from the slender 
blade-bone to abut against the breast- bone, and the arch is further 
complete by the clavicles which, instead of being two separate 
slender little bones embedded in the flesh alone, here form the 
merrythought or furculum, which above abuts against the coracoids 
and scapulae, and below is firmly fixed to the sternum. 

The anterior extremity of the pectoral limb is greatly reduced, 
exhibiting only rudiments * of the parts we saw in the cat's fore- 
paw. 

The pelvic girdle is at once more complex and less complete than 

* There are two carpal bones ; three i two are separate save at their ends), and 
metacarpals united in one mass (though I three digits with one or two phalanges. 



464 THE CAT. [chap. xm. 

in the cat. As has been said, it unites dorsally with many vertebrae 
in one large mass, while ventrally it is widely open. The acetabu- 
lum is perforated. 

The fibula is but a needle of bone fused below with the tibia, but 
the most surprising thing is, the apparent absence of a tarsus alto- 
gether. 

Directly below the tibia there is only one long bone, which repre- 
sents three metatarsals united in one and supporting three digits, while 
at the lower end of its inner side is a small separate metatarsal bone 
for the fourth digit. In fact, in the rook, the tarsus has partly 
united with the tibia, and partly with the metatarsus, so that the 
joint is placed not between the tibia and the tarsus, but in the 
middle of the tarsus itself, which has become blended with adjacent 
parts — the proximal part of the tarsus anchylosing with the tibia, 
while its distal part anchyloses with the tarsus. 

As in the cat, so here, there are only four digits, but in the rook 
it is the representative of the outermost or little digit, not of the 
hallux, which is absent. Counting from within outwards, the 
numbers of the phalanges are two, three, four and five, a different 
number for every digit. 

The spinal marrow has the lower parts of its canalis centralis 
expanded, while at the same time in the brain the ventricles are 
small and there is no fifth ventricle. 

The smaller hemispheres are also not connected by any corpus 
callosum, and instead of corpora quadrigemina there are two lobes 
called optic, placed one on each side in a lateral and depressed 
position. The two Eustachian tubes open into the alimentary canal 
by a single aperture. 

The great artery, the aorta, sends out only one branch, which 
arches over the right bronchus. The right auriculo-ventricular 
valve is muscular and not merely membranous as in the cat. 

The lungs are not freely suspended in the thorax, but are fixed 
to the back of its cavity, and the bronchi do not divide dichoto- 
mously within the lungs. Moreover, they communicate with air- 
sacs, which not only extend within the body but even enter certain 
of the bones, which are thus themselves filled with air. Thus the 
circulating and respiratory structures are such as to give to their 
functions an even greater perfection than in the cat. This perfec- 
tion is needed for the almost constant activity of the bird, and the 
enormous muscular power it has to exert in flying. Where the 
trachea divides into the two bronchi there is a special arrange- 
ment of parts called the syrinx, or " lower larynx," the upper larynx 
(which corresponds with the larynx of the cat) being much smaller. 

The ureters do not open into the bladder, but into a chamber or 
reservoir (the cloaca), into which the bladder also opens, while the 
cloaca itself opens on the surface of the body. It is also into this 
cloaca that the posterior end of the alimentary tube opens, and not 
on the surface of the body. Into it also open the ducts from the 
testes in the male, and the (here single) Fallopian tube of the 



chap, xiii.] THE CATS PLACE IN NATURE. 465 

female. Both testes and ovaries are enclosed in the abdominal 
cavity, and in the rook there is no urethra or prostate or Cowper's 
glands, and no penis or clitoris, vagina or uterus, or any mammary 
glands. No placenta of any kind is formed, but the allantois is 
directly respiratory. It lines the egg shell, which is porous enougb to 
admit of the respiratory gaseous interchange taking place through it. 

In almost all the differences from the cat here enumerated, all 
birds agree with the rook, whatever may be their habit of life or the 
general external influences to which they are exposed. 

Thus the ostrich and apteryx cannot fly, and yet their pectoral 
limb is formed on the type * of that of the crow, as also is the sub- 
aqueous paddle of the penguin, a bird as incapable of flight as the 
ostrich. 

§ 17. The cat is then, as a mammal, distinguished from birds in 
that: 

(1) Its skull has a "petrous bone," and a mandible formed of two 

pieces only and suspended directly from the squamosal. 

(2) Its auditory ossicles are minute and take no part in 

suspending the mandible. 

(3) There are two occipital condyles. 

(4) Its skin is furnished with tair. 

(5) Its cerebrum is large, with a corpus callosum, and its corpora 

quadrigemina are small. 

(6) Olfactory nerves being present, there is a cribriform plate. 

(7) Its ear has a complex, spiral cochlea. 

(8) Its solitary aortic arch, arches over the left bronchus. 

(9) No air-cells communicate with the lungs. 

(10) It has no syrinx, but a large and complex larynx. 

(11) Its lungs are freely suspended in the thoracic cavity. 

(12) It has a complete diaphragm. 

(13) Its posterior nares open far back within the mouth. 

(14) The ulna is larger than the radius. 

(15) The skeleton of the extremities is arranged on a different 

type. 

(16) The pelvis extends less forwards. 

(17) The ankle-joint is not an intertarsal one. 

(18) The proximal and distal parts of the tarsus do not anchylose 

with the tibia and metatarsus respectively. 

(19) The caudal vertebrae do not end in a " ploughshare f bone." 

(20) The red-blood corpuscles are not nucleated. 

(21) The right auriculo-ventricular valve is membranous only 

and not muscular. 

(22) It has no feathers. 

(23) The corpora quadrigemina are not laterally depressed. 

(24) The Eustachian tubes open separately within the alimentary 

canal. 

* In these birds the breast-bone though . f Neither do they in the extinct meso- 
wide is keelless. | zoic bird— the Archeopteryx. ,. 

H H 



466 THE GAT. [chap, xiii, 

(25) No digit of the pelvic limb has more than three phalanges.* 
The first eight of the foregoing characters, together with the 12 th, 
17th, and 20th, serve to distinguish the cat, as a mammal, from the 
whole of the province Monocondyla. It is also distinguished from 
all back-boned animals which are not mammals, in the follow- 
ing points : 

(1) The mandible consists only of one bone on each side, and 

directly articulates with the squamosal. 

(2) The malleus and incus are only small auditory ossicles. 

(3) The periotic bones anchylose together to form a petrous bone 

before anchylosing with parts of the occipital. 

(4) There are two occipital condyles co-existing with a distinct 

basisphenoid. 

(5) There is a cribriform plate unless olfactory nerves are absent. 

(6) There is but one aortic arch, which arches over the left 

bronchus. 

(7) Two auricles and two ventricles co-exist with a membranous 

right auriculo-ventricular valve, and a single aortic arch. 

(8) There is more or less hair. 

(9) There is a corpus callosum and fifth ventricle. 

(10) The red-blood corpuscles are not nucleated. 

(11) There is a complete diaphragm, which acts as the main 

respiratory organ. 

(12) The male has a penis traversed by the urethra. 

(13) The female is provided with mammary glands. 

Such then is the cat's place in nature, so far considered. The 
cat is a beast, or mammalian back-boned animal, because it has the 
anatomical characters above enumerated, and the varying degrees 
of its divergence from the other provinces and classes which go to 
make up the sub-kingdom Yertebrata, are to be estimated according 
to the variations of structural conditions which have been indicated in 
the lists of characters above given. It remains to see the rank and 
position which the cat may claim amongst its fellow mammals. 

§ 18. Besides the creature to the study of which this book is 
devoted, all the animals most familiar to us and most generally- 
valuable to us — as our dogs and our domestic cattle — are members 
of the class Mammalia. The name " beasts " is in more or less 
general use to denote the various brute animals which belong to the 
class ; but since man himself — the most individually numerous of 
all the large animals — is, structurally considered, also a member of 
it, the name " Mammals " will be henceforth always exclusively 
here employed to denote the creatures which compose it. 

Hitherto we have been occupied but with sub-kingdoms, pro- 
vinces, and classes ; the characters of subordinate groups of the 
Invertebrate sub-kingdoms having no bearing upon the question as 
to the cat's place in nature. Now, however, such subordinate 

* This can only be affirmed of the i some aquatic mammals (Cetacea) has 
pelvic limb, because the pectoral limb of | digits with more than three phalanges. 



chap, xm.] TEE CAT'S PLACE IN NATURE. 467 

groups, as they exist in the class Mammalia, must he more 
or less considered; for the cat helongs to a mammalian genus 
which comprises the majority of the forms reviewed in the twelfth 
chapter of this work. The whole of these forms — all the lions, 
tigers, leopards, jaguars, pumas, ocelots, lynxes, cheetahs, and other 
living and extinct cats — form together a group which has the 
zoological rank of a " family," and it is a family of an " order " divisible 
into " sub-orders," while the order itself is one of various others which 
go to make one of the three very unequal "sub-classes" which 
together make up the whole class Mammalia. The class Mammalia 
has been now compared with all the other classes of back-boned 
animals, and the vertebrate sub-kingdom with all other sub- 
kingdoms of animals. It remains to compare the cat's sub-class with 
the other mammalian sub-classes ; the cat's order with the other 
orders of its sub-class ; the cat's sub-order with the other sub-orders 
into which its order is divisible, and the cat's family with the other 
families which, together with that family itself, make up the sub- 
order within which the cat is included. This done, we have but to 
consider the results arrived at in the twelfth chapter as to genera 
into which the cat's family is divisible, m order to exhaust our 
present inquiry by attaining a final and satisfactory answer to the 
question " What is the cat's place in nature ? " and to understand 
the cat's taxonomy. 

Closely allied to the domestic cattle — our sheep and oxen — are 
all bisons, buffaloes, goats, antelopes, deer, giraffes, chevrotains,* 
llamas, and camels. Less closely allied, but still allied, are all 
peccaries and swine, and the hippopotamus. With these, also, may 
be associated the rhinoceros and tapirs, and lastly all asses, quaggas, 
zebras, and horses. All these creatures together constitute one 
order of mammals, the order Ungulata, into which the little hyrax, 
the " coney " of the English Bible, may or may not be admitted, 
according to the view of classification adopted. 

Somewhat* allied to ungulates, but distinct from them, are the 
elephants, which form the order Probosctdea, an order which once — 
with its various species of elephant, large and small, its Mastodon 
and Dinotheria — was rich in species and individuals, and was widely 
distributed over the world's surface. 

Somewhat related to them again is the numerically very small 
order Sirenia : an order now containing only the Manatee and 
Dugong, although another genus, Rhytina, still existed at no distant 
period, f 

Other marine creatures, really very different in nature from the 
Sirenia, were long classed with them. These are the many kinds of 
whalebone-whales, porpoises, sperm-whales, and dolphins, which 
together make up the order Cetacea. Yet other marine creatures, of 
less decidedly and exclusively aquatic habits, are the seals and sea- 

* Very small animals, commonly called i f It was exterminated in the year 
in error musk-deer. | 1768. 

H H 2 



468 THE CAT [chap, xiil 

lions (or sea-bears), which constitute the order Pinnipedia. All kinds 
of apes, together with man, and certain animals called " Lemuroids," 
form another mammalian order- — one to which Linnaeus gave the 
name Primates. Lemurs are animals with fox-like snouts, but with 
paws like those of apes, which inhabit the geologically remarkable 
island of Madagascar. " Lemuroids " are lemurs and creatures like 
lemurs, and such are found either in Madagascar, or more or less in 
the vicinity of the Indian Ocean, though a few reach western Africa. 

The only beasts which truly fly are bats, which form an order by 
themselves. It is well named Cheiroptera, since their wings are 
enormously spread-out hands with webbed fingers. When 
Australia was discovered, very many new and strange mammals 
were there found ; differing amongst themselves greatly in external 
appearance, mode of life, food, and size. Large kangaroos browsed 
over the plains, taking the place elsewhere occupied by browsing 
ungulates. Many phalangers climbed the forest trees, with feet the 
great toes of which were prehensile, acting like " hind-thumbs," as 
in the feet of apes. Certain small quadrupeds with molar teeth 
bristling with sharp points — the bandicoots — fed on insects, 
while the wombat, a squat- shaped sluggish animal, was specially 
qualified for nibbling and grinding vegetable food by two large 
incisors above and below, followed (after a wide diastema) by flat- 
surfaced molars. Some Australian mammals were enabled to take 
prolonged jumps by means of lateral skin extensions which procured 
for them the name of " flying opossums " (Petaiirus, &c). Other 
mammals were more or less fierce beasts of prey, with teeth 
remotely like those of tbe cat, and with blood-thirsty habits. Such 
were the native-cats or Dasyures, and the Thylacine or Tasmanian 
wolf. All these various mammals, however different in form, 
together constitute but a single order, M4.Hsupialta, an order into 
which the insect-eating and flesh-eating opossums of America must 
also be admitted. Two other Australian forms justly excited wonder 
when discovered. One of these was the platypus or Ornitho- 
rhynchus (with a squat, hairy, body, short limbs, and a duck's bill) ; 
the other was the Echidna — an animal covered with spines, and with 
a slender snout devoid of teeth, a long tongue, and strong nails 
suited to its ant-eating habits. These two forms by themselves 
constitute the order Monotremata. 

In South America other edentulous, strong- clawed ant-eaters are 
found, which, with the South African Aard-vark (Orycteropus), the 
scaly pangolins (Manis), the sloths and armadillos, with the huge 
extinct Megatherium and Mylodon, together make up an order called 
Edentata. Insect-eating beasts (mostly small, and having amongst 
them the absolutely smallest mammal), such as the hedgehog, the 
Asiatic Gymnura, the moles, shrews, elephant-shrews, water -shrews, 
tupaias, tanrec (Centetes), Soknodon, Potomagale, the golden mole, 
&c, are all united in one ordinal group, which bears the name of 
Insectivora. Another very large ordinal group has teeth like those 
of the wombat. This is the order Rodentia, which contains all 



chap, xiii.] THE CAT'S PLACE IN NATURE. 4(59 

rats, mice, squirrels, guinea-pigs, porcupines, beavers, jerboas, rat- 
moles, and rabbits and bares. Some rodents are, like the flying 
opossums, fitted to flit through the air in long jumps, by means of 
the wide extensibility of the skin of their flanks, which, when 
stretched out, acts as a parachute — such are the so-called " flying- 
squirrels " and the genus Anomalurus. 

Lastly we have the order to which all the kinds of cats belong, 
together with all pole-cats, civet-cats, hyaenas, bears, weasels, dogs, 
wolves, and foxes — the order of flesh-eating mammals par excellence, 
or Carnivora. 

These various orders of the class Mammalia are grouped together 
into three sub-classes as follows : — 

The order Monotremata is an order so exceedingly different from 
all the others that there can be no doubt (in spite of the few species 
it contains) of its forming a sub -class by itself. It forms the sub- 
class Ornithodelphia. 

The order Marsupialia differs much less from the great bulk of 
mammals than does the order Monotremata, nevertheless it also is 
reckoned as forming a second sub class by itself. It forms a sub- 
class much more numerous than the sub-class Ornithodelphia, yet it 
contains but very few species when compared with the number of 
species contained in the third sub-class. The second or Marsupial 
sub-class bears the name Didelphia. All the rest of the mammalia — 
that is to say the whole of the orders Ungulata, Proboscidea, Sirenia, 
Cetacea, Pinnipedia, Primates, Cheiroptera, Edentata, Insectivora, 
Rodentia, and Carnivora, together make up the third and last 
mammalian sub-class, that containing the placental mammals — the 
sub-class Monodelphia. 

§ 19 Now the cat, as a monodelphous mammal, of course shares 
the characters which distinguish that sub-class from both the others. 
We have then first to see how the cat thus differs from the 
Ornithodelphia. 

The Ornithorhynchus and Echidna agree together in having an 
exceedingly rudimentary corpus callosum, a condition perhaps more 
or less compensated for by the very large size of the anterior com- 
missure. In the internal ear, the cochlea instead of being spirally 
coiled, as we saw it to be in the cat, is but slightly twisted. The 
vertebrae are not ossified by the intervention of epiphyses, and the 
shoulder-girdle is of remarkable complexity. Instead of mere 
coracoid processes, such as we saw in the cat, there are large 
coracoid bones (as in birds) with epicoracoid bones, and an inter- 
clavicle — as in many lizards. The acetabula are also perforated (as 
in birds) and the fibula sends up a large olecranon-like process, 
rendering its serial homology with the ulna strikingly evident. 
The internal tendon of the external oblique muscle of the abdomen 
is ossified, resulting in the development of two large bones, called 
" Marsupial," which are attached to the front margin of the pelvis. 
The mouth is either edentulous, or if, as in the Ornithorhynchus, 
there are teeth, then these are not calcareous but of a horny 



470 THE CAT. [chap, xm, 

texture. Posteriorly the alimentary canal opens into a cloaca (as 
in the Monocondyla) which also receives the terminations of the 
ureters and generative ducts. Thus the ureters do not open into 
the bladder, although a urinary bladder is fully formed. The penis 
is perforated by a urethra, but this does not transmit the renal 
secretion, as it is proximally discontinuous with the cystic urethra, 
and serves but for the testicular product. There are two uteri, 
which open side by side into the cloaca, so that there is no vagina 
any more than in birds — from which circumstance the name of the 
sub-class is derived. The mammary glands pour out the milk from 
numerous apertures on the surface of the skin, but these are not 
aggregated into a distinct prominence or nipple. No allantoic 
placenta is developed. Thus the cat, as a monodelphous mammal, 
diners from the lowest mammalian sub-class, the Ornithodelphia, 
by the following characters : — 

(1) There is (in the female) a vagina. 

(2) There is no cloaca. 

(3) The cystic and spongy portions of the urethra are continuous, 

and it transmits the urine. 

(4) The ureters open into the bladder. 

(5) The mammary glands have teats. 

(6) The vertebrae ossify by terminal epiphyses. 

(7) Development is effected by the help of an allantoic placenta. 

(8) The cerebrum has a large corpus callosum and a small 

anterior commissure. 

(9) The ear has a complex, spirally coiled cochlea. 

(10) The coracoids are but small processes. 

(11) There are no epicoracoids or interclavicle. 

(12) The acetabula are imperforate. 

(13) There are no marsupial bones. 

(14) The fibula has no olecranon-like process. 

(15) There being teeth * they are calcareous. 

The animals of the order Marsupialia are all much more like the 
cat in structure than are the Monotremes. Nevertheless they pre- 
sent such important divergences from the structure of monodelphous 
mammals, that the whale or bat may both be considered (they being 
both monodelphous mammals) to be much more fundamentally like 
the cat than is that opossum which has (on account of its superficial 
resemblance to our subject) been called the " native-cat." 

In all the marsupials the vagina is double — whence the name of 
their sub-class, BideJphia. Their process of development takes place 
in such wise that the young are brought forth in an extremely 
imperfect condition. They are, therefore, in the great majority of 
marsupials, sheltered for a time within a " pouch," (consisting of a 
fold of the skin of the belly) within which are the nipples. Their 
young are not developed by means of an allantoic placenta, and when 
born, are so feeble and imperfect that they are unable to suck. On 

* Some Monodelphous mammals, as we have seen, have no teeth at all. 



chap, xiii.] THE CAT'S PLACE IN NATURE. 471 

this account the milk is injected by the mother into the young 
while it hangs attached Dy its mouth to the nipple. The injecting 
action is effected by the cremaster muscle, which embraces the 
mammary glands of the females and the testes of the males. The 
testes hang in a scrotum ; but this receptacle is placed in front of 
the penis instead of, as in the cat, behind it. All marsupials have 
marsupial bones except the Thylacine, which has them represented 
by large marsupial cartilages. The internal carotid artery enters 
the cranium through a foramen in the sphenoid bone. The mandible 
has its " angle " inflected. The palate has commonly certain 
apertures due to defect of ossification. The corpus callosum is very 
small, and the anterior commissure is large. In such marsupial 
forms as are carnivorous, the molar teeth are not differentiated into 
premolars, sectorials, and tubercular teeth — as in the cat and other 
placental carnivora — and there are never six incisors above and six 
below. Thus the cat, as a monodelphous mammal, diners from 
the Didelphta in that : 

(1) The vagina is single. 

(2) The young are brought forth in a well- developed condition. 

(3) There is no " pouch " and the young can suck as soon as born. 

(4) There are never marsupial bones or large* marsupial 

cartilages. 

(5) The mammae are not embraced by the cremaster. 

(6) The scrotum being present f is behind the penis. 

(7) The internal carotid does not perforate the sphenoid. 

(8) The corpus callosum is large and the anterior commissure 

small. 

(9) The«angle of the* mandible is not inflected. { 

(10) There are six incisors in both the upper and lower jaw. 

(11) Reproduction takes place by the aid of an allantoic placenta. 
§ 20. Such being the characters which respectively distinguish 

the cat as a monodelphous mammal from both the mammalian 
sub-classes which are not monodelphous, we have next to compare 
its order with the other orders of its own sub- class Monodelphia. 

Its order, Carnivora, containing the creatures we have already 
seen it to contain, is easily distinguishable from the two orders 
Sirenia and Cetacea, because in both the latter the pelvic limbs are 
entirely wanting, or only represented by rudiments not externally 
visible. 

The Carnivora are distinguished from all animals of the order 
Edentata by possessing median upper incisors, with unequivocal canines 
and with molars provided with cutting edges or tubercular prominences 
or both. From the anteaters they differ in that they are furnished with 
teeth ; from the pangolins, in that they are not clothed with horny 
overlapping scales ; from the armadillos, in that their skin does not 
develop calcareous plates ; from the Orycteropus, in that each tooth 

* In the dog there are very small mar- I a scrotum, 
supial cartilages. J It is so however in the monodelphous 

T Not all monodelphous mammals have | mammal— the Tanrec (Centetes). 



472 THE CAT. [chap. xiii. 

lias not a number of small, parallel pulp cavities; and from the 
sloths, in that their digits are not so closely bound together by skin 
up to the roots of such enormous curved claws as to reduce the paws 
to mere hooks by which, the body may be suspended. 

From the Cheiroptera all members of the cat's order differ in not 
having the fingers enormously produced and webbed so as to form 
a pair of true wings, enabling their possessor really to fly and not 
merely to flit like a so-called flying-squirrel or flying opossum. 

The Carnivora differ from the Proboscidea in not possessing a 
long trunk or proboscis, and in not having large pendent ears, huge 
incisor teeth, and an enormous caecum. Also in having less con- 
voluted cerebral hemispheres, two canines above and below, and 
digits which are furnished with claws, i.e. are unguiculate. 

The Primates are all distinguishable from the Carnivora in that 
they are monodelphous mammals with either the pollex or hallux or 
both, so formed as to be opposable to the other digits and suitable 
for grasping. They have also a more or less developed third or 
"posterior" cornu to each lateral ventricle. None of them are 
powerful enough to be able to successfully contend with the largest 
of the cats or bears, and but for his intelligence, man himself would 
be quite unequal either to fly from or destroy such creatures. Even 
as it is, many human lives are annually destroyed by the largest 
carnivora. In the Primates, the placenta is never in the form of a 
zone round the ovum. 

The Carnivora differ from the Ungulata in that they have often 
five (always at least four) digits to each paw. Their digits are also 
unguiculate and never sheathed in horny hoofs. Their molar teeth 
also are either cutting or simply tuberculate, while the foetus is 
developed by means of a deciduate placenta almost always in the 
form of a zone round the ovum. The Carnivora also are always 
digitigrade or plantigrade, never " unguligrade," i.e., they never 
walk upon enormous nails (or "hoofs" ) as is the case with almost 
all the Ungulates. 

The Carnivora differ from the Rodentia in that they have canine 
teeth and have not got large incisors growing from permanent pulps. 
They also have the glenoid cavity for the mandibular condyle trans- 
versely, and not, as in Rodents, more or less antero-posteriorly 
extended. Moreover, though the Rodents have a deciduate placenta, 
it is never zonary. 

The Insectivora differ from the Carnivora by their less perfectly 
developed brain, not only the cerebellum but even the corpora 
quadrigemina being left uncovered by the small hemispheres, which 
are smooth or hardly convoluted. They have, besides, a relatively 
small corpus callosum and a large anterior commissure. Their molar 
teeth also have generally more numerous and sharply pointed pro- 
minences than in the Carnivora, and their molars are not differen- 
tiated into premolars and sectorial, followed by a tubercular form 
of tooth. Their bony palate is often defectively ossified, which it is 



chap, xm.] TEE CAT S PLACE IN NATURE. 473 

not in the Carnivora. With one exception* they always have com- 
pletely developed clavicles, which in the Carnivora are never more 
developed than in the cats. Their generative organs may he pro- 
vided with a sac attached to each vas deferens close to its opening 
into the urethra, i.e., they may have vesiculse seminales (which 
Carnivora never have), while the testes are never scrotal, and 
though the placenta is deciduate it is not zonary. 

Lastly, the Carnivora differ from the Pinnipedia in that their hind 
limbs are always more or less well suited for progression on land, 
being always not only capable of having the plantar surfaces applied 
to the ground, but also being free and not held together by integu- 
ment down to the ankles as they are in such Pinnipedia as can 
apply the soles of the hind feet to the ground, which none of the 
true seals can do. Tn these latter the hind legs are permanently 
stretched out in a line with the axis of the trunk and tied to the 
tail by a fold of integument, so that they act more like a caudal fin 
than like legs. Seals are also entirely destitute of an external ear 
or concha. In all the Pinnipedia the middle digit is the shortest in 
each hind foot. The brain is very large and very much convoluted, 
and there may be a very small third or posterior cornu to each 
lateral ventricle, while the olfactory lobes and anterior commissure 
are rudimentary and the lachrymal canal and bone are absent. 

Altogether it may be said that the cat*s order-— the Carnivora — 
differs from all the other Monodelphotjs mammals put together, 
in the simultaneous possession of the following common characters, 
only some of which are possessed by the various other orders : — 

(1) The brain is well developed, with cerebral convolutions (two 

or three around the Sylvian fissure), and a well-developed 
corpus callosum and small anterior commissure. Tbe 
cerebral hemispheres do not cover the cerebellum, nor 
do they contain triradiate lateral ventricles. 

(2) The eyes are well developed, with a choanoid muscle, and 

may have a brilliant tapetum, with an iris capable of con- 
tracting its aperture to a vertical linear slit. 

(3) The ears are provided with a more or less prominent concha. 

(4) The hyoid has, on each side, a short thyro-hyal and a large, 

segmented, anterior cornu. 

(5) The carpus has a scapho-lunar bone. 

(6) No extremity has less than four digits, provided with sharp, 

conical claws, and very often there are five digits so provided. 

(7) Progression is digitigrade or plantigrade. 

(8) No digit is opposable to the others. 

(9) There are always well developed canines. 

(10) The incisors are small, and there are always six above and 
six below in each jaw except in the marine otter (Enhy- 
dris), and in the fossil Eusmilus> which have each but 
four inferior incisors. 

* The African aquatic Insectivore, named Potomogale. 

y 



474 



TEE CAT. 



[CHAP. XIII. 



(11) The molars are cutting or tuberculate. 

(12) There is a milk dentition. 

(13) The stomach is simple. 

(14) The ca3cum is never very large. 

(15) There is never more than an imperfect clavicle. 

(16) The atlas has two large transverse processes. 

(17) The glenoid cavity and condyle are elongated transversely. 

(18) The zygoma arches very widely outwards and much upwards. 

(19) There are no vesiculae seminales. 

(20) The uterus is two-horned. 

(21) The placenta is deciduate. 

(22) It is almost always zonary. 

§ 21. The order Carnivora consists of a variety of genera forming 







Fig. 191.— Skull of the Panda (Ailurus fulgens). 

nine different families, which are grouped in three sets or sub-orders. 
One of these sub-orders is named Cynoidea, and it contains only 
the family of dogs, wolves, jackals, and foxes — the family Canidcp. 
The second sub-order is called Arctoidea, and it embraces the 
family of Bears, Ursidce, and the family of Racoons, Coati-mondis, 
Kinkajous, with the genus £assaris—a family called Procyonidce. 



chap, xni.J THE CAT'S PLACE IN NAJUfiE. 



475 



It also contains a third small family, Ailuridce, containing only the 
Panda (Aihtriis), and, perhaps, Aihwopus* It comprises, fourthly 
and lastly, the large family of Weasels and Otters, called Mustelidce. 

The third sub-order of Carnivora is termed .^Eluroidea, and it 
contains four families. One of these is the large family of Civets — 
Viverridce; another — Hycenidce — is made up of the Hyaenas, with 
the aberrant Hysena-like form Proteles. The third — Cryptoproctidce 
— contains the singular Madagascar animal the Foussa, and the 
fourth and last family is the family of Cats, Felidce. 

§ 22. If we compare the cat's sub-order JEluroidea with the 
Arctoidea, we find that some Arctoids differ strangely from the cat, 
especially the aquatic kinds, such as the otter, and above all the sea- 




Fig. 192.— Skull of the Bear (Ursus arctos). 



otter. Many, like the bear and badger, are completely plantigrade. 
Some have teeth which are not at all sectorial, as the bears, coati 
and AUums; while others, as the glutton (Gulo), have teeth which 
much resemble the cat's in structure. There is at least one hinder 
tubercular molar above and below, so that there are two true molars 
in the lower jaw.f In size the Arctoidea range from the smallest 
weasel to the grisly bear. Some Arctoids are frugivorous animals, 
as the sloth bear ; others are most blood-thirsty, as the weasels, 
ferrets, and glutton. 

With such varieties of form and habit, it is not surprising that 
good positive characters by which the species of a group so various 
may be united together, and at the same time divided off from the 
other sub-orders, are difficult to find. Rather, perhaps, is it sur- 
prising that any should be found at all. Yet good distinctive 
characters of a more or less recondite kind have been established. J 



* See Milne-Edwards's Recherches des 
Mammiferes, 1874, p. 321, plates 50 and 
56. " Ailuropus " is a curious mammal 
(intermediate in some respects between 
the Panda and the bears), which was dis- 
covered in Thibet by the Rev. Pere 
David, the well-known French Lazarist 
Missionary. 



f With the exception of the Pata- 
gonian weasel, called Lyncodon. 

X Partly by the late Mr. H. K 
Turner (too soon lost to science — a victim 
to a dissecting wound), and secondly by 
Professor Flower, F.R.S. See the Pro- 
ceedings of the Zoological Society for 
1848, p. 63 ; and for 1869, p. 4. 



476 



THjE CAT. 



[chap. xm. 



If we examine the basis cranil of a bear (Fig. 193) we see that its 
auditory bulla consists of a single bone, instead of two as in the cat. 
It is but little prominent, but is much prolonged outwards as the 



mice 




Fig. 193.— Part of Basis Cranii of Bear (Flower). 



a. Posterior opening of ali-sphenoid canal. 

a'. Anterior opening of same canal. 

c Condyloid foramen. 

car. Carotid foramen. 

e. Eustachian canal. 

Immediately above the right-hand end of the 
line leading from the letter c, is a large 
opening— the foramen lacerum anterius— 
at which the carotid artery reappears, after 
having traversed the petrosal, and bending 



round the skull to re-enter the skull at this 

foramen. 
g. Glenoid foramen. 
I. Foramen lacerum posterius. 
m. Mastoid process. 
ma. Meatus auditorius externus. 
o. Foramen ovale. 
p. Par-occipital process. 
s. Stylo-mastoid foramen. . 



floor of the bony meatus auditorius externus (ma). Towards its 
hinder inner end is a considerable foramen (car) for the internal 
carotid artery, which here enters the petrosal, and having traversed 



CHAP. XIII.] 



TEE CAT'S PLAGE IN NATURE. 



477 



it, emerges at the foramen lacerum anterius (just within and 
behind the opening of the Eustachian canal), and bending round 
re-enters the skull, in a backward direction, at the same foramen. 
The paroccipital process (p) is somewhat triangular, and projects 
downwards, outwards and backwards, standing quite aloof from the 
bulla. The mastoid process (m) is widely separated from the par- 
occipital, and is more or less prominent. The condyloid foramen (c) 
can be plainly seen, and is not sunk into a common opening with 
the foramen laceruni posterius. A foramen which gives exit to a 
vein — the foramen glenoideum (g) — is conspicuous just in front of the 
meatus auditorius externus. A large canal is formed by the ali- 
sphenoid, which throws out a lamina of bone to embrace the external 
carotid artery. The passage thus enclosed is (as has been before 




Fig. 194. — Vertical Section through Tympanic Cavity of Bear (Flower). 



am. Meatus auditorius externus. 
BO. Basi-oecipital. 
Car. Carotid canal. 
e. Eustachian canal. 



g. Glenoid canal leading to glenoid foramen. 
Sg. Squamosal. 
2'. Tympanic bone. 
t. Tympanic ring. 



mentioned) called the alisphenoid canal. Its posterior aperture (a) 
is its own exclusively, but its anterior opening (a) includes within 
it that of the foramen rotundum. 

When the auditory bulla is seen in section (Fig. 194), the simplicity 
of its cavity is apparent. 

The above-given cranial characters are. with the exception of that 
of the presence of an alisphenoid canal and of the emergence 
anteriorly of the internal carotid artery, characters of the whole of 
the Arctoidea,* and to them may be added the further distinctions, 
that there is no caecum whatever to the intestinal canal ; that the 
penis contains a large bone, which is not grooved, but which is dilated 



* Certain exceptional details are presented by Ailuropus. 



478 



TEE CAT. 



[chap. xm. 




Fig. 195.— Skull of the Fox (Vulpes bengaknsis) 




Fig. 196.— Skull of Wolf (Flower). 



a. Posterior opening of ali-sphcnoid canal. 
af. Its anterior opening. 
am. Meatus auditorius externus. 
c. Condyloid foramen. 
car. Carotid foramen. 
e. Eustachian canal. 

Above the right-hand end of the line which 
leads from the letter c, is the foramen 



lacerum anterius, where the internal carotid 
emerges, and then doubling back, re-enters 
the cranium. 

g. Glenoid foramen. 

I. Foramen lacerum posterius 

m. Mastoid foramem 

o. Foramen ovale. 

p. Par-occipital process. 



chap, xiii.] THE CAT'S PLACE IN NATURE. 479 

behind and bilobed in front ; that there are no Cowper's glands, and 
that the prostate is rudimentary, or exists only as a thickening of 
the wall of the urethra, and does noi, form a distinct prominence. 

The sub-order of dog-like creatures, the Cynoidea — which contains 
but one family, Canidce — differs strikingly from the cat's sub- order. 
The Cynoids have two posterior tubercular molars above and below, and 
their normal dentition consists of four premolars and two molars in 
the upper jaw, and four premolars and three molars in the lower jaw ; 
though one singular form, Otocyon, has four premolars and three 
molars on each side of each jaw. If we examine the basis cranii 
we find a smooth, rounded and simple auditory bulla, but neither 
does it send out externally so prolonged a process (Fig. 196, am) for 
the meatus auditorius externus, as in the Arctoidea, nor is the carotid 
foramen (car), though of good size, distinctly visible on its inner 
border, for that foramen is, as it were, withdrawn within the 
foramen lacerum posterius, into which it opens. Nevertheless, the 




Fig. 197.— Section of Auditory Bulla of Doo (Flower). 

am. Meatus auditorius externus. *. Septum. 

BO. Basi-occipital. Sq. Squamosal. 

car. Carotid canal T. Tympanic bone. 

c. Eustachian canal. t. Tympanic ring. 
g. Glenoid canal. 

internal carotid follows the same course and emerges anteriorly 
(there doubling backwards), as in the bears. The paroccipital 
process (p) is long and projecting, and its anterior surface is more 
applied against the bulla than in the Arctoid sub-order. The mastoid 
(m) is distinct, but small. Both the condyloid and glenoid foramens 
are very conspicuous, the former opening upon a bony ridge, and 
being quite distinct from the foramen lacerum posterius. There is 
a well- developed alisphenoid canal {a, a ). When a section is made 
of the bulla (Fig. 197) a very incomplete septum (s) may be seen to 
spring from its anterior wall, in the same position as that in which 
we saw the complete septum of the cat to take origin. 

These cranial characters are possessed by all the Cynoidea, as are 
also the following ones : — The caecum is not only present, but rather 
elongated, and almost always folded on itself. The bone of the 



480 



THE CAT. 



[CHAP. XIII. 



penis is straight, wide, depressed and grooved. There are no 
Cowper's glands, but there is a salient prostate. 

Finally, we come to the cat's sub- order, the -ZEluroidea. Therein 
the following characters (which we have already seen to exist in the 
cat) exist universally, so far as the structure of its component species 
is known. 

(1) The auditory bulla is much dilated, smooth, rounded, and 
generally divided into two chambers bv a septum. 




..UliU*^ 



Fig. 198. — Skull and Dentition of Paradoxurtjs Crossii. 



(2) The bony meatus auditorius externus is short, and only 

produced in front, or else is imperfectly ossified below. 

(3) The paroccipital process is, as it were, flattened against the 

auditory bulla, to which it is much more closely applied 
than it is in the Cynoidea. 

(4) The mastoid is never salient, and often not to be distin- 

guished. 



CHAP. XIII.] 



THE GATS PLACE IN NATURE. 



481 



(5) The carotid canal is generally small, and the foramen lead- 

ing to it inconspicuous. 

(6) The condyloid foramen almost always opens into the foramen 

lacerum posterius, and is therefore inconspicuous and con- 
cealed. 

(7) There is generally no glenoid foramen. 

(8) The csecum is small and simple, and may occasionally be absent. 

(9) The bone of the penis is almost always small and irregularly 

shaped, and may be wanting. 

(10) There are Cowper's glands. 

(11) There is a salient, lobed prostate. 

(12) The teeth are never as tubercular as in the dogs and bears. 

(13) An ali- sphenoid canal may be present or absent. 

§ 23. In considering creatures which make up the cat's own sub- 





Fig. 199.— The African Civet (Viv^rra civetta) 
(Floiver). 
a. Ali-sphenoid canal. 
am. Meatus auditorius externus. 
c. Condyloid foramen. 
car. Carotid foramen. 



Fig. 200.— The Paradoxttre (Paradoxurus 
bomlar) (Flower). 
e. Eustachian canal. 
I. Foramen lacerum posterius. 
o. Foramen ovale. 
p. Par-occipital process. 



order, it may be well to begin with the large family of the Vivekrid^. 
This family includes a large number of forms, such as the African 
civet and the Asiatic zibet ( Viverra) ; the genets (Genetta), of which 
one is an inhabitant of Europe ; the paradoxures (Paradoxurus), 
animals inhabiting Eastern India ; the ichneumons (Herpestes) ; the 
suricate (Ryzcena) ; the mangue (Crossarchus) ; the animal named 
Cynictis ; the long-whiskered, short-tailed creature, Cynogale, and 



i i 



482 



THE CAT. 



[CHAP. XIII. 



the large, arboreal, and in many respects exceptional Viverrine — the 
Binturong (Arctitis). 

The Viverridce have a rather elongated head and mnzzle, and they 
have almost always two tubercular molars in the upper jaw and one 
in the lower. Of true molars (as distinguished from premolars) 
there are two above and two below on each side of each jaw. The 
teeth may vary in shape, from largely sectorial — though never as in 
the cats — to mainly tubercular. The caecum is small and simple, or 
may be, by very rare exception, absent. Cowper's glands are 
present, and the prostate gland is salient and lobed. The penis 
may be devoid of any bone, or if there is one it is small and 
irregular in shape. Often, as in the civet, there are largely 
developed scent-glands. 

In the cranial characters the whole of the Yiverrines show great 



c&m 




Fig. 201. — The Ichneumon (Herpestes ichneumon) (Flower). 



a. Posterior end of ali-sphenoid canal. 
a'. Its anterior termination. 
am. Meatus aiiditorius externus. 
c. Condyloid foramen. 
car. Carotid foramen. 



e. Eustachian canaL 

I. Foramen lacerum posterius. 

m. Mastoid. 

o. Foramen ovale. 

p. Par-occipital process. 



uniformity. There is generally a distinct ali-sphenoid canal The 
auditory bulla is large, smooth and rounded, and consists of two 
portions separated by a nearly complete septum, much as in the cat, 
except that the chamber which corresponds with the inner chamber 
of the cat's bulla, is posterior in situation The carotid canal is 
larger than in the cat, and may run through a canal in the petrosal 
(as in Herpestes), or may be merely represented by a groove on 
the inner side of the auditory bulla. In Herpestes and allied forms, 
the artery, after emerging, runs along for a short distance before 
re-entering the cranium. The par-occipital process is widened, 
spread out, and closely applied to the posterior surface of the 



chap, xiii.] THE CATS PLACE IN NATURE. 483 

auditory bulla, and the condyloid foramen is concealed within the 
foramen lacerum posterius There is either no glenoid foramen 
or it is minute. The mastoid process is quite indistinct, or but little 
prominent. The bonv meatus auditorius externus is either very 
short — extending but little outside the tympanic ring (as in Viverra, 
Fig. 199) — or if, as in the Suricates, it is prolonged, its floor is 
medianly fissured. 

The next family is that of the Hyaenas, Hymntdm, which also 
contains the curious and aberrant South African mammal, the Aard- 
vark {Proteles) an animal erroneously supposed by some naturalists 
to be related to the dog. 

In this family the teeth are either, as in the hyaenas, remarkable 
for their strength and cutting power, or, as in Proteles, for their 
extreme weakness. In the hyaena there are four upper premolars, 
all sectorial, especially the hindmost, which is much like that of the 
cat, as is also the minute, solitary upper tubercular molar. In the 
lower jaw there are three premolars and one molar — all sectorial 
like those of the cat, though less perfectly formed for cutting, 
because the hyaena's* teeth are broader and stronger, and more suited 
for the bone-crushing action in which they are employed. The 
Aard-vark has four weak, small molar teeth in either jaw, each such 
tooth being separated by a diastema from the tooth nearest to it. 

As to the structure of the skull, the hyaenas have a smooth, oval, 
prominent bulla, which is perfectly simple within its cavity, not even 
showing a trace of a septum for its division into two chambers. 
Yet, as in theViverrines, it is considerably more prominent posteriorly 
than in front, so that if a septum was developed, the chambers would 
probably be placed one in front and one behind. There is no all -sphenoid 
canal. The carotid foramen (Fig. 202, car) is small, and situated a 
little behind the middle of the inner margin of the bulla. The par- 
occipital process is spread out over the posterior surface of the bulla, 
but forms also a rounded prominence projecting b ck wards (p). 
The mastoid process is also slightly prominent. The bony meatus 
auditorius externus is short, yet the anterior portion of its floor is 
produced outwards as a rather pointed process. The condyloid 
foramen is concealed, and the glenoid foramen is minute or absent. 

Proteles agrees with the hyaenas in these cranial characters, except 
that in it the bulla is divided by a septum into two chambers — one 
being quite anterior and the other posterior — and that the mastoid 
and paroccipital processes do not stand out from the skull. As to the 
generative organs, Cowper's glands and a salient prostate are present 
in both Proteles and Hycena, while no bone has been observed in the 
penis of either. In both, also, the caecum coli is simple and very 
small, and there are large scent-glands. In both, also, there are 
normally not less than fifteen dorsal vertebrae. 

The third family, Cryptoproctid;e, contains only a single species 
— namely, a fierce animal (of the size of a large cat) to which the 
natives of Madagascar give the name " Foussa." 

It is an animal much like a cat, but with a longer head. It has 

I I 2 



484 



THE CAT. 



[chap. XIII. 



large ears and a long tail. Its claws are retractile, but it does not 
walk like the cat on its toes, but applies nearly the whole plantar and 
palmar surfaces to the ground. It may therefore be said to be 
plantigrade. It was originally made known to science, and named 
m a paper published by Mr. E. T. Bennett.* The young specimen 
described by him came from Mr. Telfair of Mauritius, who declared 




Fig. 202.— Hyaena (Hycena striata) (Flower). 



am. Meatus auditorius externus. 
c. Condyloid foramen. 
car. Carotid foramen. 
e. Eustachian canal. 



1. Foramen lacerum posterius. 

m. Mastoid. 

o. Foramen ovale. 

p. Par-occipital process. 



it to be " the most savage creature of its size I ever met with ; its 
motions, power and activity are those of a tiger, and it has the same 
appetite for blood and destruction of animal life." 

Its teeth are very like those of the cat, save that it has an 
additional premolar below and, for a time also, one above, but the 
latter soon falls away. 

The skull is more elongated, in proportion to its other dimensions, 
than is that of the cat. 



* In the Transactions of the Zoological Society, p. 137, plate 21. 



CHAP. XIII.] 



THE CAT'S PLACE IN NATURE. 



485 



The basis cranii (Fig. 205) shows a distinct ali- sphenoid canal (a, a') 
and carotid foramen near the anterior end of the inner margin of the 
bulla, which is divided by a septum into two chambers. The inner 




Fig. 203.— The Foussa (Cryptoprocta jerox). 



of these chambers is quite posterior in situation, and the bulla is 
much more prominent behind than in front. The paroccipital 
process is not prominent, but is applied to the bulla, and the mastoid 




Fig. 204.— Skull, of Cryptoprocta ferox. 



process does not project outwards. The condyloid foramen is con- 
cealed, and there is no glenoid foramen. 

The dorsal vertebrae are thirteen in number, and the lumbar are 
seven. 



486 



THE CAT. 



[CHAP. XIII. 



The scapula is less rounded than that of the common cat, hut 
there is a largely-developed metacromion. The supra-condyloid 
foramen of the humerus is extremely large. The metacarpals and 
metatarsals are relatively shorter than in the cat. The pollex is 
more developed, but the hallux is very different, being completely 





205.— Basis ceanii of Cryptoprocta ferox 
(Flower). 

a. Posterior opening of ali-sphenoid canal. 

a'. Its anterior opening. 

am. Meatus auditorius extemus. 

c. Condyloid foramen. 

car. Carotid foramen. 

e. Eustachian canal. 

I. Foramen lacerum posterius. 

o. Foramen ovale. 

p. Par-occipital process. 




>. — The Pads of the Feet of the 

Foussa (Cryptoprocta ferox). 



A. The 

B. The 



of the fore-paw. 
of the hind-paw. 



formed, instead of being, as in the cat, a mere rudiment. It has a long 
metatarsal and two phalanges, the distal end of the digit reaching 
nearly to the distal end of the first phalanx of the adjacent toe. 

The naked pads on the feet are much more extended than in the 
cat,* in harmony with the almost quite plantigrade habit of the Foussa. 
There is a long bone to the penis, compressed, slightly curved, not 
grooved, but slightly dilated at each end, more so posteriorly. 

The anatomy of the soft parts is, unfortunately, as yet unknown. 

§ 24. Such being the nature of the families of the cat's sub-order, 



* See ante, Figs. 9 and 10, p. 25. 



chap, xiii.] THE CAT'S PLACE IN NATURE. 



487 



other than the family of cats themselves (FeUdce), we may now 
contrast the latter (i.e., the FeUdce,) with each of the former. 

The different kinds of cats all agree with the common cat in 




Fig. 207. — Part of the base of the Skull of the Tiger (Felis tigHs). A portion of thf. 
Auditory Bulla has been removed to show its interior. The Cavity of the 
Inner or Posterior Chamber is exposed (Floiver). 



am. Meatus auditorius externus. 

c. Condyloid foramen. 

ear. Carotid foramen. 

e. Eustachian canal. 

I. Foramen lacerum posterlus. 

m. Mastoid process. 



o. Foramen ovale. 

p. Par-occipital process 

r. Fenestra rotun a. 

s. Septum between the chambers. 

* The aperture of communication. 



structure, save as regards the details already pointed out in the last 
chapter. We may then proceed to sum up the main points in which 
the cat's family differs from the other three families of the sub- 
order JEluroidea, as follows. 



488 



THE CAT. 



[chap, xiil 



The Felidje differ from the ViverridvE, in that in the Felidce : 
(1) The head is more rounded ; 

The limbs are generally longer in proportion to the trunk ; 

The claws are generally more completely retractile ; 

The teeth are more sectorial, and the premolars and 
tubercular molars are fewer, there being never more than 
one tubercular molar (an upper one) in any living species ; 

There are no conspicuous scent-glands ; 

There is no ali-sphenoid canal save in certain extinct genera ; 

The division of the bulla is hardly perceptible exteriorly, 
while the two chambers into which it is internally divided 
are not placed one quite behind the other ; 

The carotid foramen is always very small, and the carotid 
canal indistinct, except in some extinct genera ; 



(2) 
(3) 
(4) 



(5) 
(6) 
(?) 



(8) 




Fig. 208.— Section of the Auditory Bulla of the Tiger (Flower). 



am. Meatus auditorius externus. 
BO. Basi-occipital, 
e. Eustachian canal, 
t c. The inner chambers. 
o c. The outer chamber. 



* The aperture of communication between the 

chambers. 
PL Petrosal. 
s. Septum. 
Sq. Squamosa 






(9) The par- occipital process (though applied to the bulla) may, 
in large species, develope a marked process ; 
(10) The meatus auditorius externus is never medianly fissured 
below. 

The Felidce differ from the Hy^enid^e in that : 

(1) Their head is more rounded ; 

(2) Their claws are retractile ; 

(3) The body does not droop so much posteriorly ; 

(4) The teeth are more perfectly sectorial in form; 

(5) The premolars are less numerous ; 



chap, xiii.] THE CAT'S PLACE IN NATURE. 489 

(6) The bulla is, at least in existing species, divided into two 

chambers, which are not placed completely one behind the 
other ; 

(7) The bulla is most prominent towards its inner, not towards 

its hinder border ; 

(8) The bony meatus auditorius externus is not produced an- 

teriorly into an outstanding process ; 

(9) There may be a small bone to the penis ; 

(10) There are no conspicuous scent-glands ; 

(11) There are only thirteen dorsal vertebrae. 

The Felid^: differ further from the true Hyaenas (i.e., the 
Hyaenas as distinguished from Proteles) in that : 

(1) Their teeth are less powerfully formed for crushing; 

(2) The bulla is divided by a septum ; 

(3) The carotid foramen is generally still less conspicuous. 

They further differ from Proteles in that : 

(1) Their teeth are much stronger and larger relatively, and 

more closely approximate ; 

(2) The chambers of the bulla are not quite one behind the 

other. 

The Felid^e differ from the CryptoproctidtE in that : 

(1) They are quite digitigrade ; 

(2) Their skull is relatively shorter and rounder ; 

(3) Their premolars are (except in Archcelurus) less numerous ; 

(4) The chambers of the bulla are not quite one behind the 

other ; 

(5) There is no ali-sphenoid canal, save in some extinct genera ; 

(6) The supra- condyloid foramen is of moderate size ; 

(7) The metacarpals and metatarsals are relatively longer ; 

(8) The pollex is very small, and the hallux a mere rudiment ; 

(9) The naked pads of the feet are much less extended ; 
(10) The bone of the penis is small. 

§ 25. We have now before us as complete a statement as the 
author can give of the relations which exist between the cat's family 
and all other living organisms whatsoever. 

As to the subordinate groups contained within the cat's own 
family, i.e., its genera, we saw in the last chapter that all known 
cats living and extinct can be arranged in eleven sets of kinds, to 
which the names Felis, Cyncelurus, JElurodon, Archcelurus, Dinictis, 
Nimravus, Pseuclcelurus, Hop lop ho a ens, Pogonodon, Machcerodus, and 
Eusmilus, have been given. We now see what was meant by saying 
that these groups have each the value of a " genus." As to the 
relations which exist between the feline genera, we now also see that 
the exceptional characters presented by Dinictis and Archcelurus are 
peculiarities which cause those genera to have a certain resemblance 
to the Viverrine family. 

In the last chapter we recognized the fact that an extreme 



490 THE CAT. [chap. xiii. 

specialization of structure is presented by Machcerodus and Eusmilus, 
and that Cyncelurus is the most exceptional form amongst living- 
felines, and one in which some of the distinctive characters of its 
family (e.g., the retractility of the claws), are poorly developed. 
The cat's genus, Felis, is one which, while it well exemplifies the 
characters of the family to which it belongs, yet does not exhibit 
any of those characters developed either in an extreme or in an 
aberrant manner. This statement needs some explanation. Every 
group of animals containing various species consists of certain kinds, 
which are more or less alike, and differ but little from an ideal 
standard which is the type of such group. Such kinds are 
normal forms. Besides these, there are generally certain other 
kinds which are peculiarly modified in one way or another, depart- 
ing more or less widely from the normal structure. Such divergent 
kinds are said to be aberrant or abnormal. Also both "normal" 
and " aberrant " forms may be either what is called specialized or 
generalized. " Specialized" creatures are such as have an ex- 
ceptional organization of a definite kind. " Generalized " creatures 
are such as resemble the general run of animals to which they are 
more or less closely related, but have the distinctive characters of 
their group poorly developed. But besides the specialized and 
generalized normal forms, there may be other normal forms which 
are neither of these, but adhere closely to the type and express it in 
its intensity, yet without an} r one-sided development of it. These 
are typical forms. The full meaning of these terms can only be 
made clear by examples, for which it is necessary to refer to some 
other group of animals with which the reader may be acquainted, 
or with which he can easily become so. Let us then take, as examples, 
species of the well-defined group of ruminating beasts. Amongst 
them we have creatures which adhere to the normal structure, but 
yet its characteristic features are in them but poorly developed. 
They are then generalized normal forms, as, e.g., that small South 
American deer, the yenada or pudu (Pudu humilis). Others, which 
adhere to the normal structure, may carry it to an intense but some- 
what one-sided degree of development. Such would be specialized 
normal forms, as, e.g., the elk or the four-horned antelope. Others 
again may diverge from the general type in the direction of other 
creatures outside their group. Such would be generalized aberrant 
.forms, such as the camel and llama, or as the chevrotains; whilst 
others may diverge from such type in a special direction of their 
own, and such would be called specialized aberrant forms, as, e.g., 
the giraffe. 

Finally, others will be normal, and yet with the characters special 
to the group strongly developed, i.e., they will be typical forms, as, 
e.g., the red deer or the Indian antelope. 

To apply these remarks to the Felicia?, we have an example of 
a "generalized normal form " in the cheetah, Cyncelurus. The lion 
is an example of a "specialized normal form." For a " generalized 
aberrant form " we must have recourse to fossils, such as Dirndls, 



chap, xiii.] THE CATS PLACE IN NATURE. 491 

and, above all, Arcluvlurus, as also for specialized aberrant forms, 
of which Eusmilus and JSIachairodus smilodon afford us excellent 
examples. Finally, as the expression of the typical or fully-developed 
normal form of the cat's family, we have the species which go to 
make up the maneless cats of the typical genus Felis, of which Felis 
catus will stand as a very good example. 

But if the cat is thus the typical genus of its family, in what 
relation may its family be said to stand to the other families of its 
order thus considered ? Of all the families of that order, the dog's 
family, Canidee, seems to be the most generalized aberrant one. For 
while it possesses the general characters of its order without carrying 
them to an intense degree, it shows certain resemblances to forms 
outside its order.* 

The bears, on the other hand, are specialized aberrant forms, as 
they depart from the normal standard of the order in a special 
direction of their own, as also do the otters and several other forms 
of Carnivora.f 

As to the mass of the Mustilidae and Viverridee, they may be 
considered to be normally generalized carnivores, since they possess 
the ordinary carnivorous characters moderately developed. It is not 
easy to point out any certainly normally specialized families — any 
family, that is, which has the characters of the order in an intense 
degree, but developed, as it were, in a one-sided manner. Such 
characters seem only present in certain exceptional Felidce, such as 
Machcerodus and Eusmilus. If so, then the Felicia?, as a whole, 
must be held to be the typical family of the whole order ; for they 
carry the carnivorous type of structure to an intense degree, but one 
which is in the direct line of development which the order Carnivora 
has followed. Carnivorous beasts generally have sharp claws, often 
more or less retractile, but none have them so perfectly developed in 
these respects as have the cats. Almost all carnivorous beasts have 
teeth more or less well adapted for killing prey and cutting flesh, but 
none have their teeth so admirably adapted for these purposes as 
have the cats. The cats are then carnivora par excellence, and they 
carry out the type of their order to its highest-known and most 
perfectly harmonious expression. 

But the cats are not only such highly-developed Carnivora. Some- 
thing may also be said in favour of their being the highest of mam- 
mals — the very flower and culmination of the mammalian animal 
tree. 

Spontaneous activitv and sensitiveness are the special characteristics 
of animal life, and with both these powers the cats are largely endowed. 
We have recognized the perfection of their organs of movement, and 
that of the very substance of their bones and muscles, as well as the 
great perfection of their special senses. It may be objected, how- 
ever, that the activities and sense perceptions of certain other beasts 

* E.g., to certain marsupials. I leptes), the binturoug (Arctitis), and also 

+ Such as e.g. the kinkajou {Cerco- I P-ioteles. 



.492 THE GAT. [chap. xni. 

are, in their own various ways, as highly developed as are those of 
the Felidce. It is certainly very true that it is only through the 
possession of perfectly-formed hones and muscles, of a delicate sense 
of hearing, or of far-reaching vision, that antelopes, hares, and such 
creatures, escape their carnivorous pursuers. But then they use 
their organization for escape. The organization of the cat-tribe may 
then he deemed superior, because it is not only excellent in itself, 
but because it is fitted to dominate the excellences of other beasts. 
Thus considered, the Carnivora would rank first amongst mam- 
mals, and the cats would rank first amongst the Carnivora. Man, 
however, is a mammal, and therefore to affirm this would be to 
affirm the inferiority of our own species.- But man's superiority is 
mental, it resides in his intellect, not in his peculiarly-formed great 
toe, hand, pelvis, or other corporeal peculiarity, Man is to be 
regarded in two lights — as a truly intellectual being, and as animal 
with a certain organization. Viewed in the firsb mode,, he stands quite 
apart from and outside of the whole visible creation, and has simply 
no place whatever in any scheme of biological classification. Con- 
sidered merely in his capacity as an animal, he has a very definite 
place in such a scheme, but it is by no means certain that his place 
is at its summit. Our powers of locomotion and of sense perception 
are quite inferior to those of very many beasts, and though our brain 
is large, both absolutely and relatively, yet such are the variations 
in this respect, presented by animals of different groups and by 
different animals of the same group, that the naturalist would be a 
bold one who should venture to affirm that a brain-classification of 
vertebrate animals — to say nothing of the Invertebrata — would be 
a satisfactory one. The close bodily resemblance of apes to man 
gives them then no just claim to a rank above that of the Carnivora, 
since such a claim only reposes on their bodily resemblance to our- 
selves. As to their intelligence, no evidence seems to be forthcoming 
that it is superior to that of the dog or of the elephant, though their 
close likeness to ourselves gives to their tricks a deceptive appearance 
of rationality which we must always be careful adequately to discount 
if we would correctly estimate their real worth. 

The apes are, like the dogs and the elephant, superior perhaps 
in cognitive psychical endowments to the cat, but yet any such dif- 
ferences between these animals are merely differences of degree and 
not of kind, like that which we have seen to exist between the cat- 
mind and our own. 

It may, perhaps, be objected to these observations, that biological 
classification is (as has been pointed out in this work) a morpho- 
logical and not a physiological classification ; that it reposes not on 
function but on structure. This is most true, and nothing could 
well be more preposterous than a proposal to classify all creatures 
according to their psychical endowments. Such a classification would 
tear away ants and bees from insects obviously like them, and associate 
them with beavers, and it would utterly confuse all biological science. 
But though it is true that animals must be classified according to 



chap, xiii.] THE CAT'S PLACE IN NATURE. 493 

their structural characters, yet it is obvious that the value of and the 
relations between structural characters themselves, cannot be con- 
sidered except by reference to conditions which are not structural. 
Therefore, as in considering the question, which of all the groups of 
animals is to rank highest, we must estimate the value of their 
structural characters, we must necessarily, in so doing, go beyond 
facts of structure themselves, i.e., we must refer to the purposes they 
serve, that is to physiology. 

It is therefore true that " something may be said in favour of cats 
being the highest of mammals/' if man is considered merely in his 
animal capacity — in which alone he can be brought into comparison 
with other organisms. 

But whether or not this eminence be allowed to the cat, there can 
be no question but that it is the most highly-developed type of 
carnivorous* mammalian life — -the most perfect embodiment of the 
idea of a " beast of prey." Such, then, is certainly the "cat's place 
in nature : " It is u member of the typical genus of the typical 
family of carnivorous placental mammals — mammals being the suck- 
giving, tied-brained * class of back-boned animals. 

* I,t., with their cerebral hemispheres united by means of a corpus cailosum. 



CHAPTEE XIV. 



THE CAT S HEXICOLOGY. 



§ 1. Every animal has definite relations to the various influences 
which on all sides surround and act upon it, and which constitute 
what is called its " environment." Every animal has existed for a 
certain definite time and within certain limits of space. It has been 
favoured, or the reverse, by the physical forces (that is, by conditions 
of climate, including temperature, moisture, &c), and its existence 
has been related in various ways to that of other living creatures. 
The science of Hexicology is (as was shortly stated at the end of the 
first chapter) the study of all these more or less complex relations. 

§ 2. The cat-group, Felidce, has now to be considered as thus 
related to its environment, and we may consider first its relations 

with PHYSICAL CONDITIONS. 

As to heat, that the domestic cat loves warmth is what everyone 
must have observed. Almost all the larger cats, and the great bulk 
of the smaller kinds, are inhabitants of the warmest regions of the 
globe. No cat dwells in the extreme north with the polar bear, 
while no region is too hot for certain species of Felts. 

Yet we have seen that the Ounce and Felts scripta are dwellers 
on the snowy heights of Thibet, and that the tiger ranges to the 
Amoor river, while the group of lynxes — the caracal excepted — are 
northern forms, two varieties, possibly two species, being found in 
Scandinavia and Canada. Moreover, in earlier times, existing 
species, such as the lion, extended into colder climes than they now 
inhabit, while in the earliest prehistoric human period that great cat, 
Felts spelea, was an inhabitant of England, protected perhaps by a 
very ample furry coat, such as that which protects the Ounce of 
Thibet to-day. Yet the differences as to fur are after all very small 
compared with the differences as to climate. Therefore, the feline race 
being thus able to live in countries of very different temperatures, 
must have a considerable internal power of regulating and sustain- 
ing the temperature of the body, and concomitantly with this faculty 
we find that no cat falls into a winter sleep, i.e., no cat hibernates. 

As to light, though the great majority of cats dwell in climates 
where daylight is intense, yet they mostly remain in repose while 
the sun is above the horizon, and prowl about in twilight or at night. 

Still certain kinds are diurnal, and from observations made at the 



chap, xiv.] THE CAT'S HEXICOLOGY. 495 

Zoological Gardens it seems that it is (as might be expected) the 
cats with pupils which can be contracted into minute linear openings 
which are the most nocturnal. Yet the tiger in spite of its circular 
pupils seeks its prey at night. 

With regard to moisture, though no cats are aquatic, and though 
none take to the water save with more or less (generally with 
extreme) reluctance, yet many (like the tiger and the jaguar) 
habitually haunt the banks of rivers or pools, because they more 
easily obtain their prey in such situations. Certain kinds, more- 
over, live more or less upon fish (as F. viverrind), and the domestic 
cat's relish for fish is very marked. Yet the Felidce are a family of 
either distinctly terrestrial or else arboreal mammals. 

The Felidce as a rule do not drink much water, but it seems* that 
the smaller kinds drink more in proportion to their size than do the 
larger species. The lion is found in desert regions, and when in 
captivity drinks very little. 

As to the degree of rarity of the atmosphere which they can 
endure, we have seen that the Ounce ranges from 9,000 to 18,000 
feet — the latter altitude being one at which man breathes with much 
difficulty. 

§ 3. The geographical relations of the cat-family are instructive 
and somewhat complex. As was long ago remarked by Buffon, the 
great cats of the Old and New Worlds are markedly distinct. The 
lior, tiger, leopard, ounce, clouded tiger, cheetah, and caracal, with 
a variety of smaller cats, are all inhabitants of the Old World only. 
The puma, jaguar, ocelot, jaguarondi, eyra, collocollo, the pampas, and 
one or two other cats are exclusively inhabitants of the New World. 
It is only amongst the lynxes that we find a form which is common 
to both these worlds — the Canadian and North European lynxes being 
probably but varieties of one species. With this exception no wild 
cat found in America is also found out of it. The New World is not 
so rich in cat-species as is the Old, nor do its largest kinds, the puma 
and jaguar, equal the largest kinds of Africa and Asia. 

A further geographical distinction may be drawn amongst Ameri- 
can cats themselves. Of its varieties of lynx, F. maculata descends 
as far south as Mexico, while the puma alone extends to high latitudes 
in both North and South America. We may therefore distinguish the 
region north of Arkansas and Louisiana as the region of lynxes and 
the puma; while Mexico, with parts of Arkansas and Louisiana, and 
all America south of Mexico may be said to be the region of the 
puma, jaguar, ocelot, and all other American cats. 

Strange to say the West Indian Islands, though some of them, as 
Cuba and Hayti, seem admirably suited to shelter and support 
species of Felidce, are entirely destitute of them.f 

In the Old World, certain other geographical divisions may be 
similarly established. We have seen that the lion, leopard, caracal, 

* Mr. A. D. Bartlett has kindly sup- I species of the cat family, 
plied me with information as to the f Trinidad is to be reckoned as a part 

drinking habit in confinement of different [ of the South American continent. 



496 THE CAT. [chap. xiv. 

and common cheetah certainly exist in both Asia and Africa. With 
these exceptions, however, the two tropical continents of the Old 
World seem to have a quite different cat population. 

In Africa we have, peculiar to it, the serval with its allied species 
or varieties, F. rntila, F. negkcta, F. servalina, F* celidogaster, and 
F. scncgalenis, as also F. caligata and C. lanea. Moreover, though the 
serval is said to occur in Algeria, and F. caligata is a North African 
form, the other varieties are found in Guinea, Gambia, Sierra Leone, 
and Senegal. Africa south of the Sahara may therefore be considered 
as richer in cats than the more northern portion of that continent, 
especially as it is south of the Sahara that the kinds common to 
Africa and Asia are principally found. There is reason, moreover, 
(from the analogy of the geographical distribution of other animals) 
to suspect that the felines now found north, of the Sahara may be 
immigrants from the more southern portion of Africa. 

Just as in America we found the West Indies to be devoid of 
cats, so, strange to say, the great island of Madagascar, jn spite ot 
its forests and numerous animal population, is similarly without a 
single species of cat. 

In Asia we find a further subdivision possible between its northern, 
south-western, and south-eastern portions. In the north, i.e., north 
of the Himalayas, we have the ounce, the tiger, a lynx (F. isa- 
bellina), the steppe cat (F. Manul), the leopard (in Japan), and 
the species or varieties before described as F. microtis, F. tristis, 
F. scripta, and F. chinensis. 

In South-western Asia we have the lion, with certain forms 
common to this and other Asiatic regions, such as the tiger, leopard, 
Indian wild cat, and some others. 

In South-eastern Asia we have the clouded tiger (F. macrocelis), 
F. planiceps, F. badia, F. marmorata, F. megalotis, F. aurata, F. 
minuta, with the tiger, leopard, and others common to other 
regions. 

The tiger, as we have seen, descends through the Indian Archi- 
pelago, with the exception of Borneo, down to the island of Bali, 
which is its furthest limit south. 

In the immense and hot island of New Guinea, in Celebes,* in 
Australia, and in New Zealand, there is no single indigenous cat of 
any kind. 

In Europe, we have two species of lynx and also the wild cat, 
while within the historical period we had the lion also. Thus the 
world may be divided according to the distribution of its cat-popu- 
lation into two great divisions — those of the Old and New Worlds 



* Muller (Verhand. over de Natuur- 
Hjke Geschiedenis Zool. Leyden, 1844, 
Part 1., Over de Zoogdiemen van den 
Indischen ArchipeL, p. 54) speaks ^ of 
reports received from natives of the exist- 
ence of a panther and wild cat in Celebes. 
Though it is not impossible that there 



unlikely that one should be found in that 
island, 'and Dr. A. B. Meyer, of Dresden, 
writes tome to say that the animal meant 
is probably a Paradoxurus, which cer- 
tainly exists there. He also tells me he 
obtained two specimens of Felis minuta 
from Zebu, in the Philippine Islands. 



may be a cat in Celebes, it is extremely | F. minuta also inhabits Borneo. 



chap, xiv.] THE CATS HEXICOLOGY. 497 

respectively, with, further subdivisions into : (1) America north of 
Arkansas and Louisiana; (2) Arkansas and Louisiana, Mexico, 
Central and Southern America ; (3) Africa, the part north of the 
Sahara being somewhat distinct ; (4) Asia north of the Himalaya ; 
(5) Southern Asia — slightly separable into (A) a south-western, and 
(B) a south-eastern portion; and, finally, (6) Europe. A certain 
affinity exists between Europe and Northern Asia on the one hand, 
and in a less degree, between Europe and North America on the 
other ; while South-western Asia has a certain affinity to Africa. 
The West Indies, Madagascar, the Philippines, the Moluccas, New 
Guinea, Australia, and New Zealand, are all devoid of any natural 
feline population, while Asia is certainly the great home of the cat 
family. 

Such being the geography of the Felidce, what relation does it 
bear to the geography of other animals ? 

§ 4. It has been found that (regard being had to the geographical 
distribution of animals of all kinds) the earth's surface may be most 
conveniently divided zoologically (the polar regions not being included) 
into the six following regions : (1) Palae- arctic ; (2) Ne-arctic ; (3) 
Indian ; (4) Ethiopian ; (5) Neo-tropical ; and (6) Australian. 

The Pal^-arctic region includes all Europe, with Iceland and 
the Azores ; Africa, north of the Sahara, with the Canaries and Cape 
Verde Islands; and all Asia (with Japan), north of the Himalaya 
and the tropic of Cancer, except the southern part of China, Assam, 
and some parts adjacent, w 7 hich belong to the Indian region. 

Characteristic of this region are horses and asses, mules, sheep, 
goats, camels, fallow-deer, the ibex, the chamois, many w T arblers, 
grouse, pheasants, tits, magpies, true vipers, chameleons, and various 
Batrachians, such, as the gigantic salamander, the land salamander, 
the proteus, and various other efts, as well as many frogs and toads. 
Twenty genera of fresh- water fishes (belonging mostly to the carp, 
perch, and salmon families) are peculiar to this region. As to 
insects, there are fifteen peculiar genera of butterflies. Here and 
there are also found certain monkeys, flying foxes, the genet, hyaena, 
polar bear, walrus, and hyrax. 

This zoological region does not exactly correspond with our feline 
geographical divisions, yet it to a certain degree harmonizes with, 
them, embracing, as it does, the European, North Asiatic, and North 
African feline divisions in one. 

The Ne-arctic region of general zoological geography, includes 
North America down to and (on elevated land) somewhat south of 
the tropic of Cancer. This region is destitute of apes, hedgehogs, 
wild horses, asses, swine, true oxen, goats, or dormice. It has 
hardly any sheep or antelopes, and no flycatchers, starlings, true 
grouse, or pheasants. On the other hand, it has peculiar forms, 
such as racoons, peccaries, certain antelopes, certain pouched rats, 
the prairie dog, certain porcupines, and also turkeys, crested quails, 
tufted grouse, and passenger-pigeons, the mocking-bird, the canvas- 
backed duckj and some humming birds. Besides these, it has rattle- 



498 THE CAT. [chap. xiv. 

snakes, the curious lizards, Chirotes and Phrynosoma, and various 
'terrapins, besides alligators, but no chameleons or true vipers. The 
tailed-Batrachians have their head-quarters in this region. Besides 
other genera peculiar to it may be mentioned : the Menopoma, 
Menobranchus, Amphinama, and Siren, as well as the axolotl. Cer- 
tain ganoid fishes are also noteworthy, such as Amia, the bony pike 
(Lepidostcus), and Scaphirhynchus. 

This region mostly corresponds with our North American cat- 
region, but extends further southwards, as our- North American 
feline region excludes Mexico and Southern Texas, and even parts of 
Louisiana and Arkansas. 

The Oriental or Indian region embraces India, Burmah, 
Southern China, the Malay Peninsula and Archipelago, including the 
Philippine Islands and the island of Bally, but excluding Lombok, 
Celebes, and the islands south and east of these. Amongst its animal 
inhabitants are many monkeys. There are also many deer, and but 
few antelopes.* Elephants and rhinoceroses are found there, and also 
chevrotains (Tragulus), pangolins, and a tapir. Amongst its birds 
may be noted the peacock, the argus and fire-backed pheasants, true 
fowls, hornbills, bee-eaters, many pigeons, parrots, cuckoos, and wood^ 
peckers, and a few sunbirds (Nectarinidce). As to reptiles, we find 
a multitude of snakes — amongst them the cobras and curious TJro- 
peltidm, or shield-tailed snakes — but no rattle-snakes — with many 
lizards, including chameleons and the little flying-dragon (Draco). 
We also find crocodiles and gavials, but no alligators, while in the 
Indian Ocean we find sea-snakes. Frogs and toads are numerous, 
but efts are wanting, save as immigrants from the Palaa-arctic region. 
We, however, meet with the singular Ophiomorpha, or snake-like 
creatures of the frog's class, i.e., of the class Batrachia. 

This region then is a very well defined one, and corresponds with 
our South-eastern Asiatic feline region. It is remarkable that the 
island of Bally is the extreme limit of the Indian general zoological 
region as well as of the South Asiatic feline region. 

The Ethiopian region is made up of Africa, south of the Sahara, 
with Arabia, the Seychelle islands, Mauritius, and Madagascar. It 
agrees with India in having elephants and rhinoceroses ; but zebras, 
quaggas, certain hogs, the hippopotamus, the giraffe, the aquatic 
musk-deer, and Cape ant-eater (Orycteropus), are all peculiarly 
African. Africa is also specially remarkable as the home of multi- 
tudes of antelopes of many different kinds, great herds of which 
range over its southern plains. There are, however, no bears, deer, 
true oxen, goats, or sheep. Peacocks, pheasants, and jungle fowls 
are also wanting amongst its birds, while in their place we find the 
guinea fowls. The secretary bird, Balceniceps, the Balearic crane, and 
ostrich, are forms peculiar to Africa, which is also the great home of 
the weaver-birds and sun-birds. Reptiles abound — tortoises, lizards, 
and snakes, amongst which latter (as in India) there are cobras, but 

* Amongst them is the four-horned antelope. 



chap, xiv.] THE CAT'S HEXICOLOGY. 499 

no rattle-snakes. Crocodiles exist, but neither alligators nor gavials. 
There are no efts, but there are Ophiomotpha, and many frogs and 
toads, Dactylethra being the most remarkable of the latter. Amongst 
fishes, we have the curious ganoid, Polt/pterus, and one form of 
Lepidosiren. 

This general zoological region agrees with the corresponding feline 
region, save that the latter is less distinct from that part of the con- 
tinent which is north of the Sahara, and has nothing to do with the 
islands above named. Madagascar, however, is remarkable, not 
only for the absence of cats, but for possessing a very peculiar 
animal population of lemurs and lemur-like forms, and as the 
home of that exceptionally cat-like Yiverrine, the Foussa — Crypto- 
proctaferox. 

The Neo-tropical "regiox of general zoological geography comprises 
America south of the tropic of Cancer, together with the West Indies, 
and includes the greatest forest region in the world. It has a number 
of peculiar monkeys and bats, with two river- dolphins found nowhere 
else. It has also the coati-mondi, kinkajou, and tapir ; but there 
are no elephants, rhinoceroses, horses, asses, or hippopotamuses. 
There are peccaries also instead of hogs. Altogether devoid of 
antelopes, goats, sheep, oxen, or camels, there are deer and llamas. 
Rodents abound, and there are many absolutely peculiar, such as 
the paca, the viscacha, the chinchilla, the guinea-pig, and its 
gigantic cousin, the capybara, preyed on by the jaguar. But the 
neo-tropical region is remarkable for the presence of a group of 
animals found nowhere else whatever. This is the group comprising 
the sloths, ant-eaters, and armadillos. Opossums also are very 
numerous, and of many species of different sizes, and seem to take 
the place of the insect-eating beasts (Insect ivora), which are here 
conspicuous by their absence. Amongst Birds, we have, in the first 
place, the beautiful humming-birds, with toucans, jacamars, mot- 
mots, todies, macaws, curassows, and tinamous. Specially note- 
worthy, also, are the American ostrich, or rhea, the hoazin (Opis- 
t/wcomus), the cariama, and the horned-senamer (Palamedea). 

There are very many reptiles, and amongst them are both croco- 
diles and alligators, but no gavials ; an extensive family of Iguana- 
like lizards, the ameiva and its allies, but no chameleon. There are 
many snakes, including the boa-constrictor and rattle- snakes, but no 
cobras, or true vipers. Batrachians are represented by Ophiomorpha 
and many frogs and toads, including the celebrated Pipa of Suri- 
nam. A few efts also exist in the mountains towards the north. 
Amongst fishes may be mentioned the largest fresh-water fish in the 
world (Sudis gigas), the electric eel, the Trygon family of rays, and 
a Lepidosiren. The very numerous carp family, however, is here 
unrepresented. 

Thus this rich general zoological region agrees with the South 
American feline region save that the latter extends further north, 
while the former embraces the West Indian islands which are 
excluded from the South American cat region. 

K k 2 



500 THE GAT. [chap, xiv 

Finally, the Australian region is made up of Australia, with 
Tasmania, New Guinea, Celebes, the Moluccas, and islands of the 
Malay Archipelago up to and including Lumbok, and also of New 
Zealand and the Polynesian Islands. 

This great region is distinguished as the home of the marsupial 
and monotrematous mammals. 

Only in the part which approaches the Indian region do we find 
any ape or civet cat, with an ox (the anoa), hogs, deer and some 
squirrels. Flying foxes, however, exist even in Australia itself. 
As to birds, there are no vultures or woodpeckers,- or true finches 
or pheasants, while we have, as absolutely peculiar to the region, 
birds of paradise,* honeysuckers (Me lep hag idee), lyre-birds, bower- 
birds, cockatoos, many parrots, the brush-tongued lories, the mound- 
making Megapodius, the emeu, the cassowary, and (in New Zealand) 
the apteryx. It is also the head-quarters of the group of kingfishers, 
and it has many pigeons, including the crowned pigeon and the 
hook-billed Didunculiis. There are also large goatsuckers, and a 
variety of weaver-birds and sun-birds. A multitude of snakes 
exist, and very many poisonous . ones, but no true vipers and no 
rattle-snakes. As in India, we find gavials as well as crocodiles, 
but no alligators. Only in the Malayan part of the region are 
there any land tortoises. Absolutely peculiar reptilian forms are 
the Pi/gopus, the frilled lizard, the Moloch lizard, and above all (in 
New Zealand) the lizard Sphenodon.f There are no Ophiomorpha, 
and no efts, but there are very many frogs and toads. As to fresh- 
water fishes, we have the very noteworthy Ceratodus (an ancient 
triassic form here still surviving), while both the perch and carp 
families are wanting. 

New Zealand is very remarkable for the almost entire absence of 
indigenous mammalian life — marsupial, no less than placental. 
There, birds are almost the highest animals below man, and there, 
until his arrival, they held undisputed sway as represented by the 
huge creatures belonging to the genus Binomis. 

The Australian region then is not merely distinguished by an 
absence of cats, but by the presence of an animal population which 
could hardly have co-existed with them. In the West Indies and 
Madagascar, cats may be absent merely through the accident of the 
non-introduction into those parts of the earth's surface of a large 
number of mammalian forms of life, amongst which the cats were 
included. Yet we do find there some mammals more or less allied 
to cats ; but their numbers are few, while the place of the Carnivora 
is not taken by a great variety of other forms remote from them in 
structure and affinity. In Australia, however, while the whole sub- 
class to which the F elides belong is conspicuous by its absence, it is 
replaced and represented by a multitude of creatures belonging to 
another sub-class, i.e., to the Bidetphia. Thus the Australian 

* New Guinea forms. 

f A last survivor of a group of forms long passed away. 



chap, xiv.] THE CATS HEXICOLOGY. 501 

region may be considered as a sort of negative feline region, the 
emphatically " catless " portion of the globe. 

§ 5. We must next consider the relations of cats to Time, and 
first with respect to individual life. The cats of largest size appear 
to live longest. The domestic cat lives ordinarily for about twelve 
years, and eighteen years is the greatest age for which the Author 
has obtained certain evidence. The lion is said however to live for 
forty years, and the well-known lion named "Pompey," which died 
in the Tower of London in 1760, had lived there, it is asserted, for 
no less than seventy years. This seems, however, to be a fable. 
The Author has not been able to ascertain with certainty that the 
lion lives beyond thirty years. 

As to the period during which existing kinds of cats have lived 
in times geologically recent, we must have recourse to history and to 
deposits such as those amongst which have been found the prehistoric 
remains of earlier races of man. As to the existence of Felicia? in more 
ancient periods, and as to the period w T hen genera which are now 
extinct nourished, evidence has to be sought for amongst the fossils 
contained in the rocks and deposits of different geological dates. 

It has already been said that lions existed in South-eastern 
Europe in the time of Xerxes. These may have been survivors of 
the huge cat Felts spelea (the so-called cave lion). But whether 
this was the case or not, it is certain that large extinct kinds, 
together with the leopard and other smaller forms (including the 
wild cat), ranged over Europe and England in prehistoric periods of 
very different dates. 

§ 6. Before passing in review those genera of cats which have 
become extinct, it may be w r ell to state briefly some elementary facts 
of geology, an acquaintance witn which is necessary for a correct 
appreciation of the relation of the cat to past time. 

The outer crust of the earth consists of more or less horizontal 
layers of different materials deposited from salt or fresh water, and 
known as strata. In these are often contained evidences of past 
animal life in the shape of (1) real bones, (2) pseudomorphs or 
aggregations of mineral matter which have exactly taken the place 
of real organic objects which have disappeared, (3) moulds external 
or internal, or (4) casts of moulds of such objects — all these four 
kinds of relics being what are called " fossils." 

The various " strata " were of course deposited at successive 
times, and the time of the deposition of each is called its " period," 
or " epoch. " But for subsequent disturbance, the most ancient 
strata would always be, as they generally are, the deepest. 

The uppermost and most recent accumulations of sands, clays, 
and gravels form w r hat are called the " recent deposits," anc these are 
not counted as forming any part of the proper geological strata. 

The strata beneath these are classified in three great groups, 
belonging respectively to three great epochs. 

The first or uppermost, and least ancient group, consists of strata 
called the tertiary or cainozoic strata. 



502 THE OAT. [chap. xiv. 

The second, or next deeper and more ancient group, is formed 
of strata, termed the secondary or mesozoic strata. 

The third, or deepest and most ancient group, comprises the 
strata named the primary or paheozoic. 

The Palaeozoic, or primary rocks, are made up of the following 
groups of strata, or " formations : " beginning with the oldest — 1, 
the Laurentian; 2, the Cambrian; 3, the Silurian; 4, the Devonian 
and Old Red Sandstone ; 5, the Carboniferous (including the Coal 
Pleasures), and 6, the Permian. 

The Mesozoic, or secondary rocks, are made up of: 7, the Triassic 
formation or Trias, including the New Red Sandstone and the 
Rhoetic beds ; 8, the Jurassic formation, including the Lias, the 
Oolite, and the Purbeck beds, with the Solenhofen slates of Bavaria, 
and 9, the Cretaceous formation, including the Wealden, the 
Greensand, and the Chalk. 

The Cainozoic, or tertiary rocks, consist of the three forma- 
tions known as: 10, the Eocene; 11, the Miocene, and 12, the 
Pliocene, and these three last formations are each subdivisible 
into a lower, or more ancient, and an upper, or more recent, 
portion. Deposits of the most recent pliocene times are distinguished 
as Pleistocene. 

The Eocene rocks in the form of gravels, sands, clays, and lime- 
stones, are widely distributed, and vary considerably in thickness. 
They form the areas which underlie both Paris and London. They 
constitute deposits known in France as the " Phosphorites de 
Quercy " and the " Lignites of Soissonai*," * also the Wasatch 
beds of Mexico, those of Fort Bridges in the south-west corner of 
Wyoming territory, of Colorado, &c. 

The Miocene beds are widely distributed in Europe and North 
America, but are very slightly represented in England. They include 
the deposits at White River, Dakota, and the white rivers of Nebraska 
and Oregon in America, and the deposits of Sansan and Simorre 
(Gers) in France. f The deposits of Pikermi, in Greece, were 
thought to be certainly miocene, but it is doubtful now if they are 
not really of somewhat later date. 

The Pliocene formation is an extensive one in Europe, Asia, and 
the United States, as e.g., between the Rocky Mountains and the 
Missouri, and Loup River, Nebraska. It may (as just observed) 
include the reputed miocene beds of Pikermi. 

Posterior to the pleistocene deposits are those found in caves and 
other localities associated with the remains of early man, and known 
as "Prehistoric." 

§ 7. Such being the " great groups," the " formations,'' and the 
several " strata " in which fossils are found, those of the cat family 
occur as follows : 

The genus Felis is found in Greece and India, in strata of the 

* The "Phosphorites" are upper I cene ; the White Eivers of Nebraska and 
eocene, the " Lignites" are lower eocene. Oregon, and the John Day region ot 
t The Sansan beds are middle mio- ' Oregon, are lower miocene. 



chap, xiv.] THE CATS HEXICOLOGY. 503 

newer miocene or oldest pliocene age. A cat, 1he Felis media of 
Larlet, has been found in the middle miocene in France. F. 
Christolii (a cat of the size of the serval) occurs in the lower pliocene 
of France. In pleistocene times, tiger-like cats, with the leopard, 
lynx, and wild cat, were found in England. 

Felis spelcea became extinct north of the Alps at the close of the 
pleistocene age; but, as has been said, the well-know T n " lions" 
which existed in Macedonia in the time of Xerxes may have been 
surviving examples of that species. 

Machcerodus is preserved in pliocene and miocene deposits of 
Europe, India, and America, both North and South. It survived in 
England down to late pleistocene times.* 

Hoplophoneus is from the White River, Nebraska, or lower 
miocene. 

Pseudwlurus has been found in the Phosphorites de Quercy, Loup 
Kiver, Nebraska, and Sanson (Gers). It is therefore eocene and 
miocene and pliocene. 

Nimravus is a form from the White River, Oregon, and, there- 
fore, of lower miocene times. 

Dinictis is eocene and miocene, occurring as it does in the Phos- 
phorites de Quercy and the White Rivers of Colorado, Nebraska, and 
Oregon. 

Arehcelurus is from the lower miocene beds of the John Day 
region of Oregon. 

Pogonodon is from the same region as Arehcelurus. 

Eusmilus is eocene, from the Phosphorites de Quercy, and 

JElurodon is from the pliocene of Loup River, Nebraska. 

The forms which are oldest therefore, are Pseudcelurus, Dinictis, 
and Eusmilus. That is to say, the first in time for which we have 
any evidence are two genera which, in very different degrees, differ 
from the cat type and approach less specialized forms, and also one 
genus which is most extremely specialized. 

Next come Pogonodon, Arehcelurus, Nimravus, Hoplophoneus, 
Machcerodus and Felis ; that is to say, the most generalized forms 
of all the Felicias, together with extremely specialized forms. 

Nevertheless it is a fact that the genera which most approach 
ordinary non-feline carnivora — the genera namely Arehcelurus and 
Dinictis — are from the eocene or older miocene, and none of the most 
generalized forms have as yet been found in pliocene strata. 

No feline remains have been discovered in any deposit whatever 
which is older than the eocene, i.e., there are none in any mesozoic 
or secondary strata. 

§ 8. But very few mammalian remains of any kind have as yet 
been found in secondary rocks, though of course multitudes of 
mammals must have existed before the eocene strata were deposited. 
The remains of beasts first make their appearance in the upper 

* See a paper by Professor "W. Boyd I Journal ofthe Geological Society, August, 
Dawkius ou Tertiary Mammals, Quarterly I 1880. 



504 THE CAT. [chap. xiv. 

part of the trias and also in the oolite, including the Purbeck beds. 
Such remains have been found in both Europe and North America, 
and consist of the genera Microlestes and Dromatherium. Microlestes. 
is a small insect-eating beast,* of which a few teeth have been dis- 
covered. Dromatherium f is a small American mammal, the mandible 
of which bore on each side three incisors separated by short intervals, 
a canine, and ten teeth in a continuous series of premolars and 
molars. 

Other mesozoic forms are Amphitherium, Amphilestes, Phascolo- 
iJierium, and Stereognathus. 

Amphitherium % is a genus founded on a lower jaw, with three 
incisors and a canine on each side, but with a series of twelve pre- 
molars and molars. The angle of the mandible is not inflected in 
Amphitherium. 

Amphilestes § is a form similar to the last, but with teeth more 
bristling with pointed tubercles, suited for crushing the bodies of 
insects. 

Phascolotherium || had three rather separated incisors on each side of 
its mandible, a canine, and a series of only seven teeth representing 
the premolars and molars. The angle of the mandible was inflected. 

Stereognathus % is an extinct form known by a portion of a 
mandible (from the Stonesfield slate) three quarters of an inch long, 
with three teeth quadrate in form, each with three pairs of cusps, 
and not distinctly resembling those of any existing group of animals. 
These forms (except the last mentioned) have been generally 
presumed to be marsupial, from their resemblance to certain 
modern marsupials, such, e.g., as Myrmecobius, a small Australian 
opossum, with a series of nine molars, a canine, and three rather 
separated incisors on each side of the mandible. Some of these 
fossil genera also present certain resemblances in the form of the 
molar teeth, or in the position of the dental foramen, to American 
opossums (the genus Didelphys) or to kangaroo-rats (Hypsiprymnus). 
The above are the yet known secondary mammalian forms. 

When we enter upon eocene strata we come at once upon a multi- 
tude of mammalian species now passed away, some of which it will be 
well here briefly to pass in review for reasons which will appear in 
the next chapter. Amongst eocene mammalia a group of fossils may 
first be mentioned which have been associated together by Professor 
Cope under the term Creodonta.** Some of these creatures had 

See Owen's Palaeontology, p. 301. r ** See his paper on Cieodonta, read 



f L.c, p. 302 

X See Owen's British Fossil Mammals, 
p. 29. 

§ Owen's Palaeontology, p. 303, and 
Brit.. Foss. Mam. p. 58 {Amphitherium 
Broderipii). 

II Owen's Palaeontolog.y, p. 304, and 
Broderip, Zoological Journal, vol. iii., 
p. 408, x^late 40. | on March 10th, 1876 

II Owen's Paleontology, p. 308. 



before the American Philosophical Society 
in July, 1880. See also his paper on the 
Flat-clawed Carnivora of the Eocene of 
"Wyoming, in the Proceedings of the 
American Philosophical Society, vol. xiii., 
No. 90, 1873. See also Professor Flowers 
Extinct Animals of North America, a 
lecture delivered at the Royal Institution 



CHAP. XIV.] 



THE CATS HEXICOLO&Y. 



505 



claws which, unlike those of cats, dogs, and other existing carnivora, 
were nearly flat, straight and blunt. In none did the carpus 
contain a scapholunar bone, but it had two separate bones in its 
place. The jaws of the Creodonta were long and rather slender, 
containing a number of molars, all more or less alike, and (in most 
genera) all sectorial in form, instead of being differentiated into 
a few simple premolars and one large sectorial tooth, with one or 
two tubercular teeth behind it — as are the teeth of almost all 
existing carnivora. The astragalus, moreover, instead of pre- 
senting that peculiar pulley-like shape which we have seen in the 
cat, presents in almost all these creatures a plain flat surface as in 
the existing Insectivora, Eodentia, Proboscidea, and Apes. 

One of these eocene forms has been called Proviverra,by Rutimeyer, 
and Gaudry* has described a similar form (from the Phosphorites de 
Quercy), which, in many respects, reminds us of Marsupials. The 
angle of the mandible, however, is not inflected, and the bony palate 
is well ossified, and there are only six incisors in the upper jaw. 
The teeth behind the canines (of which there are six or seven in 
each jaw) are all sectorial, except the last upper one, which is. placed 
transversely. The cerebrum is so little developed that not only the 
cerebellum but even the corpora quadrigemina are uncovered by it, 
while the olfactory lobes are largely developed. 

Pterodon f is a form very similar to the last, with several sectorial 
teeth in each jaw. The structure of the feet of this animal is as 
yet unknown. 

Oxycena\ is an American mammal, some individuals of which 
were as large as the jaguar. It is closely related to the European 
form Pterodon ; but there are but two superior true molars, and the 
last of these is driven in transversely. The first true upper molar 
is the sectorial tooth, instead of the sectorial being the last premo- 
lar, as in existing Carnivora. The two last inferior molars are 
described as " tubercular-sectorial." 

Stypolophns is another American mammal, said by Cope § to 
differ from Oxycena only in certain details of tooth structure, namely, 
in having the three last lower molars " tubercular-sectorial." 

Mesonyx || is very similar to the preceding, and also American. It 
has seven inferior teeth behind the canines, but " the trochlear face 
of the astragalus is completely grooved above as in the true Car- 
nivora, and its distal end presents two facets, one for the cuboid and 
the other for the navicular bones." 



* See A. Gaudry's Enchainements du 
Monde Animal, p. 20, figs. 13-15. 
This geims is the Cynohysenodon of 
Filhol. 

f Gaudry, I. c , pp. 15-24, figs. 5 
and 6 ; see also Gervais, Paleontologie 
Fran9aise, p. 236, plates 11 and 26, and 
Filhol, Ann. des Sc. GeoL, vol. vii., 
p. 218, figs. 184-188. 

% See Cope's paper on Creodonta, read 



before the American Philosophical Society 
in July, 1880, p. 2. 

§ Cope, I. c, p. 3. 

II Cope, I. c, p. 2 ; and see also his 
paper on the Flat-clawed Carnivora of 
the Eocene of Wyoming, in Pro. of the 
Amer. Phil. Soc, vol. xiii., No. 90, 
1873. Professor Cope believes that 
Synoplotherium is really a specie* of 
Mesonyx. 



506 



THE CAT. 



[chap. XIV, 



In Miacis* on the other hand, the astragalus is flat, hut in the 
lower jaw " w r e have a near approach to the dentition of the dogs." 

DidymictiSiX from the American lower eocene, is closely allied to 
Miacis, differing only in having one less inferior tubercular molar. 

Pahvonictis f is a genus which is thought to resemble the Viverrine 
Carnivora in its teeth, save that the second lower true molar is 
rather sectorial unlike that of existing carnivorous mammals. 

Amblyctomis § seems only to differ from the last in that its fourth 
inferior premolar supports tubercles instead of a cutting edge. 

Patriofelis || is a genus founded on some fragments of a jaw ob- 
tained by Professor Hayden from near Fire Bridge, Wyoming. It 
was larger than the panther, the lower jaw being six inches long. 
It has similar characters to those of Mesonyx, save that there are 
only five lower molars instead of s^ven. 

Hyienodon^ is a well-known European form, but is found in 
America also. It has also sectorial molars in large number, but its 
brain ** was formed on the same type as that of the existing carni- 
vora. Hyamodon has a scapho-lunar bone. 

Arctocyon, the oldest mammal yet discovered posterior to the 
mesozoic epoch, is another long and well-known European fossil ft 
animal of the lower eocene. It is almost as large as a wolf, with a 
long tail and a much curved humerus with a strong deltoid ridge. 
The skull is very narrow between the middle of the zygomatic 
arches, and has large palatine foramina. The brain had large 
olfactory lobes and a small cerebrum which left the cerebellum and 
probably the corpora quadrigemina uncovered and was almost un- 
coil voluted. There were seven upper molars. The first of these 
had one root, the second and third two roots, then came a triangular 
tooth (slightly sectorial in character), followed by three tubercular 
molars, the last but one being the largest. The teeth were gene- 
rally tubercular. The ankle joint is unknown. 

Cynodon \\ is an upper eocene form, considered by M. Gaudry as 
intermediate between the dogs and civets, some species being more 
like one and others more like the other of these two types. Like 



* Cope's paper on Creodonta, pp. 3 
and 58. 

*t* Cope, I. c, p. 3. 

Z Cope, I. c, pp. 3 and 6. See also 
Gaudry, I. c, p. 19, fig. 11 ; and 
Gervais, Paleontol. Franchise, p. 225, 
plate 25, figs. 11, 12. 

§ Cope, I. c, p. 3. 

|| See United States Geological Survey 
of Territories, vol. i., p. 114, plate 7, 
fig. 20 ; and Pro. Acad. Nat. Sc. 
Philadel., March, 1870, p. 11, plate 2, 
fig. 10. 

U ^ee Gaudry, I. c, p. 14, figs. 3 and 
4 ; also Gervais, Pal. Franc., p. 232, 
plate 24 ; Filhol, Ann. des Sc. Geol., 
vol. 7, p. 162 ; and Leidy's Mammals of 
Dakota and Nebraska, Journal Acad. 



Philadel. vii., p. 39, plate 2 ; and 
De Blainville's Osteog. (Canis), p. 17 ; 
and De Laizer and De Parien, Ann. 
des Sc. Nat., 2nd series, vol. xi., 1832. 

** Nouvelles Ann. du Muse'um, 
1870, plate 6, fig. 7. 

ft De Blainville (Subursus), p. 73, 
plate 13 ; Gervais, Paleontol. Franc, p. 
220 ; and. Nouvelles Ann. du Mus., 
vol. vi,, p. 147, plate 6, fig. 4 (brain) ; 
Gaudry, I c, pp. 22-24, fig. 14. 

X+ See Gervais, Paleontol. Fran., p. 
218, plate 15 ; and Aymard, Ann. de 
la Soc. Acad, du Pny, vol. xv., p. 92, 
1851 ; also Gaudry, I. c, p. 215, figs. 
282 and 283. M. Filhol has shown the 
great variability of Cynodon. 



CHAP. XIV.] 



THE CATS HEXICOLOGY. 



507 



Avctocyon it has seven molar teeth in the upper jaw, the three 
hindmost being tubercular. The tooth next in front of these three 
is, however, of a more sectorial character than in the corresponding 
tooth of Avctocyon. 

Cynodictis * is another upper eocene carnivore which closely 
resembles Cynodon, but there are only two tubercular teeth behind 
the upper sectorial. 

Amongst the forms of life of the uppermost eocene and lower 
miocene may be mentioned Amphicyon,\ which is anotber well- 
known fossil form allied to the dogs, from which it differs in that its 
molars are less sectorial and more tubercular, and that it has a 
third upper true molar. Its limbs are more bear-like than are 
those of the dogs, and it w^as also plantigrade. 

Hymiavctos \ is a widely distributed form from the upper mio- 
cene, which has marked affinities with that just noticed ;' but its 
tubercular teeth are still larger, and specimens of most recent date 
(from the pliocene beds of Montpellier) have the tubercular teeth 
more quadrangular in form and therefore still further removed from 
the sectorial type, approaching more and more to the structure we 
now find in the bears. 

Ictithevium § is a genus of which various species have been 
described ; some as large as a leopard. They are found in the 
upper miocene or pliocene of Europe. It is intermediate in its 
dental structure between the civets and the hyaenas, in that it has 
a second upper tubercular molar, This tooth is different in size in 
different species of the genus, being very small in I. hipparionum. 

Lutvictis || is a miocene form from Auvergne which belongs to the 
family of Mustelidcp, but has a minute second upper molar. 
M. Gaudry considers it allied to the otter. 

Galccytius*^ is a miocene and pliocene form which is very fox-like, 
but has the first premolar smaller, and the third and fourth larger, 
and all the teeth are more close- set and occupy a smaller space than 
in the fox. The bones of the feet also are more robust. 

As to non-carnivorous mammals, it is evident that bats and 
opossums (Didelphys), tapirs and rodents existed in Europe in 
eocene times, while with the miocene period, apes, rhinoceroses, 
giraffes, and hippopotami co-existed in our .continent. Many 
other forms might also be enumerated, but the above list may 
be sufficient for our present purpose, as affording examples of eocene 
and miocene mammals which present more or less interesting, 



* Gervais, Paleontol. Fran?., p. 216 ; 
Filhol's Ann. des Sc. Geol., 1876, vol. 
vii., p. 66. 

f Gervais, Pal. Frang., p. 214, plate 
28 ; Filhol, Ann. des So. Geol., vol. vii., 
p. 55, figs. 23-26, and 41-43 ; Leddy, 
Mammals of Nebraska and Dakota, 
Jour, of Acad, of Nat. Sc. Philadel. vii. , 
p. 31, plates 1 and 5 ; Gaudry, I. c, pp. 
24 and 212, fig. 277. 



Z Gervais, Paleon. Frang., p. 207, 
plate 81; Gaudry, I. c, pp. 212, 213, 
figs. 278 and 279. 

§ Gaudry, I. c, pp. 208, 21 6, and 217, 
and figs. 274, 284, and 286. See also 
his Fossils of Pikerni, p. 52, plates 7, 12. 

|| Gaudry, I c.,p. 219, fig. 290. 

II Owen, Quarterly Journal of Geol. 
Soc, vol. hi., 1847, p. 55. 



508 THE CAT. [chap. xiv. 

more or less significant structural relations with the anatomy of 
the cat — mammals to which reference will have to be made in the 
following chapter. 

§ 9. The next and last point to be considered in studying the 
cat's hexicology, concerns its relations with other living beings. 

Living beings may affect each other's existence in a variety of 
ways, as food, as rivals, as indirect friends, or as direct enemies. 

Now, in the first place, the Felidce, as essentially carnivorous 
animals, can only live where they can find such other animals as 
may be necessary for their food ; and, accordingly, it is where land 
animals are most abundant, that the most numerous and largest 
kinds of the cat family are found. Certain kinds of cats also are, 
as we have seen, of arboreal habits ; and the presence or absence of 
forests ^will very importantly affect the existence here or there of 
such forms. 

The markings of cats have been supposed to be useful to them in 
various ways in their relations with other animals. The vertical 
stripes of the tiger resemble the vertical shadows of the grasses of 
the jungle amongst which it lurks, and may so aid its -concealment 
and allow its prey to approach it unsuspectingly and fatally. The 
scattered" spots of the leopard agree with the scattered spots of 
shadow amongst the foliage of the trees on the boughs of which it 
lies in wait. Similarly the hue of the lion has been thought to be 
useful to it in sandy plains. All this is no doubt true, but a multi- 
tude of instances are to be found in nature in which shapes, colours, 
and markings are most noticeable, but yet do not answer any purpose 
of the kind above referred to, and therefore to regard such relations 
as the main causes by which these markings have been brought 
about would be to rest in an explanation fundamentally inadequate. 

Animals stand to each other in the relation of rivalry where they 
each consume the same kind of food and thus tend to starve each 
other. Such a rivalry must evidently exist between different kinds 
of cats, and so prevent the coexistence of many kinds or many indi- 
viduals of the same kind in the same locality. 

Living creatures may unintentionally act a friendly part to one 
another ; inasmuch as animals of one kind may destroy creatures 
which are inimical to the existence of another kind, and thus every 
animal which destroys creatures which prey upon feline animals of 
course benefits the latter. Again, whatever creature tends to render 
abundant the food of another creature is of course the latter's bene- 
factor. Thus it has been observed that the presence of a certain 
kind of clover is beneficial to cats ; inasmuch as it is useful to a 
particular species of humble bee, the nests of which favour the 
existence of mice, which again are the food of cats. Did we know 
the analogous inter-relations which exist between the living creatures 
of tropical forests, we should doubtless come upon many curious cross 
relations and interdependencies of a similar kind, affecting their 
feline population. 

But various kinds of cats seem to have other cats for their direct 



CHAP. XIV.] 



THE CAT'S BEXICOLOGY. 



509 



enemies ; for we have seen that the tiger will even carry off and 
devour a wounded individual of its own species. 

The direct enemies of the largest and most powerful cats must he 
few ; since the great beasts which may successfully contend with 
them — elephants, rhinoceroses, &c. — being herbivorous creatures, 
are not impelled by hunger to pursue and attack them. The smaller 
cats no doubt occasionally fall a prey to other carnivora, but who- 
ever has seen a dog attack a cat, and has noted the combined ferocity 
and dexterity which the cat can exhibit with its very efficiently armed 
paws, may well doubt whether wild-cats of any kind will often be 
successfully attacked by any creatures not overwhelmingly superior 
to them in size and strength. 

§ 10. Against other enemies, however, of a very different kind, even 
the largest cats have no power of resistance. Such enemies are their 
internal and external parasites. These chiefly belong to the sub- 
kingdom Vermes. The first group is that of the thread-worms 
(Nematoklea). Of these there are several species which find a home 
in the body of the cat. They are * Ascaris mystax, Trichina spiralis, 
Trichosoma cati, Oxyuris compar, ^tronfjijlustubceformis, and Ohilanus 
tricuspis. The second group is that of the flukes (Trematoda), of which 
there are not less than three kinds, namely, Distoma lanceolatum, Am- 
phistoma truncatum, and Hemistoma cordatum. The third group, 
that of the tape-worms (Teniada), is represented by at least eight 
species as follows: — Tcenia elliptica, Tamia crassicollis, Tcenia 
semiteres (Baird), Tcenia litterata (Taenia canis-lagopodis), Tamia 
lineata, Bothriocephalus felis, and Boihriocephalus decipiens. The 
Cysticercus cellulosce, or larva of Tcenia solium, has been obtained 
from beneath the scapula, and Engelmayer found a Ccenurus in a 
cat's liver 

Dr Spencer Cobbold has observed,! " Every owner of cats must 
have, from time to time, noticed the frequent occurrence of sickness 
amongst these animals ; such fits of vomiting usually terminating in 
the expulsion of worms from the mouth. The internal parasites 
causing these attacks are small nematodes (Ascaris mystcuc) occupy- 
ing the stomach ; the females being nearly twice as long as the 
males, and sometimes measuring as much as four inches. Strongylus 
tubceformis is occasionally found in the upper intestine, and Trichina 

spiralis has been reared in the cat by experiment The most 

important of all the feline nematodes is a little w r orm, Ohilanus 
tricuspis. Whilst the full-grown Ohilanus only measures about —■ 
of an inch, its embryos are, for so small a creature, of almost gigantic 
size. The adult worm resides in the lining membrane of the stomach. 
The young of this parasite, like young Trichince, are apt to migrate within 
the body of the feline host. They thus become encysted within the 
lungs and liver ; but not in any other of the visceral organs. I have 



* For the list here given T am indebted 
to the kindness of my friend Dr. T.Spencer 
Cobbold, F.E.S. 



f See his work on The Internal Parasites 
of our Domesticated Animals, p. 124; and 
his more recent work on Parasites, p. 308. 



510 



THE CAT. 



[chap. XIV. 



seen tens, of thousands of them occupying the lungs; the infested 
animal perishing in consequence of the inflammatory action set up 
by their presence." 

" A certain number of the embryos of Olulanus escape by the bowel 
of the host. These when swallowed by mice become encysted within 
the little rodents' muscles, very much after the fashion of Trichinae. 
So that one may say the mice become olulanised in the same way 
that we say people or animals become trichinised. All this has been 
experimentally proved by Leuckart, who fed a cat with olulanised 
mouse-flesh, and afterwards found the escaped young in the cat's 
alimentary canal. As, however, these encapsuled Olulani from the 
mouse had not become sufficiently advanced in their larval * organic 
sation, Leuckart did not succeed in rearing the sexually mature 
parasite in the feline stomach. But there could be no doubt as to the 

ultimate destiny of the encapsuled young Taenia crassicollis, 

which is common to both the tame and wild animal, is obtained by 
the cat from eating the livers of rats and mice, in which organ the 
larvae of the parasite reside. Taenia lineata is found only in the wild 
cat. Bothriocephalic decipiem is extremely rare, and only known in 
the house cat. The most common of all the species is Taenia 
elliptical Taenia litterata exists in Iceland, but has also been found 
to infest the cheetah. It must therefore have a wide distribution. 

One of the most remarkable instances of the destruction of cats 
by internal parasites is that recorded by Dr. Romano, of Gemona. 
The animals perished from colic, diarrhoea, epileptiform convulsions, 
wasting, and complete prostration. All these symptoms resulted 
from tapeworms {Taenia crassicollis) within the stomach. The out- 
break occurred at Osoppo, where the fortress was over-run by rats. 
The vermin were combated by means of the cat?, and thus the most 
successful felines became the earliest victims. Those which killed the 
rats and ate their livers swallowed the iarvse of the Taenia, which 
latter, en revanche, brought about the destruction of their feline hosts.f 

Another .internal parasite is the worm-like animal Pentastoma 
alenticulatum, which is a very aberrant member of the class 
Arachniala. 

As to the cat's external parasites, they belong to two orders of 
the class Insecta (the order Aphainiptera, which contains the fleas, 
and the order Aptera, which is the order to which lice belong), 
and to the class Arachniala. 

The cat's flea,:J: Palex cati, is very like the flea of the dog, but is 
one-fourth smaller. 

The louse-like animal of the cat does not belong to the same 



* The tape-worms have two stages of 
existence, corresponding with the grub 
(or larval) condition, and the perfect (or 
imago) state of the beetle or butterfly. 

*t* See Cobbold's account (Parasites, 
I. c), abridged from Eomano's report in 
Giornale di med. vet. pratica for August, 
1877. 



X See a paper by Dr. Alexander La- 
boulbene, on Les Metamorphoses de la 
Puce du Chat, in the Annales de la Soc. 
Entomologique de France, 5th series, 
vol. ii., 1872, p. 267, plate 13 ; also 
P. Megnin's Parasites, Masson, Paris, 
1880, 63. 



CHAP. XIV.] 



THE GATS HEXIGOLOGY. 



511 



family of the order as that which contains the lice of men .and apes. 
It belongs to the family which contains the bird-lice. This parasite 
of the cat is called Trichodedes subrostratus* Its presence appears 
to cause no evil or inconvenience to its host. 

The arachnidan external parasite is a sort of itch insect, named 
Sarcoptes cati.\ It is so small as hardly to be visible to the naked 
eye, but soon accumulates in vast numbers (to the cat's extreme 
annoyance), especially on the head, ears, eyelids, and face, where it 
causes swellings as well as baldness, beginning on the back of the 
neck and head. The paws, also, are apt to be affected, as naturally 
ensues from the infected animal's vain attempts to remove the 
cause of distress. Catarrh, diarrhoea, distemper, consumption, and 
insanity, are amongst the disorders from which cats are more or 
less apt to suffer. 



* See Megnin's Parasites, p. 81 ; also 
E. Piaget's fine work, Les Pediculines, 
1880, p. 389, plate 31, fig. 9 ; and Henry 
Denny's Monographia Anoplororum 



Britannia?, 1842, p. 189. 

f See P. Megnin's Parasites, 
174 and 409. 



pp. 



CHAPTER XV. 

THE PEDIGREE AND ORIGIN OF THE CAT. 

§ 1. In the preceding chapters, the creature which has been 
selected as a type of mammalian back-honed animals, has been 
represented from various points of view. Its anatomy, physiology, 
psychology, taxonomy, and hexicology, have been successively 
treated of and the processes of individual development — the series of 
changes gone through by each individual of the cat species in reach- 
ing maturity — have been noticed. It only now remains to study 
the development of the species — that is to say, the " pedigree and 
origin," both of the cat considered as a species, and of the whole 
family of Felidce. 

To trace, as far as may be, the series of forms through which the 
existing group of cats may, with most reason, be believed to be 
descended, is, in this sense, to trace the cat's pedigree. To investi- 
gate the probable causes which have evolved such forms and 
governed such process of development, is to investigate the cat's 

ORIGIN. 

§ 2. That the various kinds of cats, and the whole cat group, 
have been evolved through the orderly operation of powers divinely 
implanted in the material creation, is a statement the truth of which 
can now, it seems, be hardly denied by any consistent persons who 
are not prepared to maintain that with the birth of every very ex- 
ceptionally formed kitten a direct intervention of the First Cause 
takes place — an intervention such as does not otherwise occur in the 
orderly sequence of purely natural phenomena. 

§ 3. In order to investigate the question of the cat's pedigree, or 
phyhgeny, its relation to other animals must be carefully borne in 
mind. 

In the thirteenth chapter it was pointed out that the cats are most 
nearly related to the Foussa (Cryptoprocta), and in a less degree to 
the other members of the family Viverridce. That they have a more 
general affinity to the whole sub-order JEluroidea, and a still more 
general one to the whole order Carnkora, and ultimately to 
mammals and to all backboned animals — beyond which they can be 
said to have no special affinities at all 

The ancestors then of the cat family must be sought for amongst 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 513 

extinct forms of carnivora nearly related to the cats and civets ; and 
the ancestors of such forms, again, must be sought amongst car- 
nivorous mammals of more and more generalized structure till we 
come to creatures from which all mammals may be supposed to have 
descended. What animals were the progenitors of all mammals, is 
as yet a matter of pure speculation, and no positive judgment can be 
formed concerning it by any prudent naturalist. Certain proba- 
bilities, however, are evident as to this and cognate questions, but 
before adverting to these probabilities, it will be well to recall to 
mind some of those existing and extinct animals to which reference 
has already been made. 

The most aberrant and generalised of all existing cats is the 
cheetah (Cyncelurus). But though this animal approaches the other 
carnivora in that its claws are less retractile than those of other cats, 
yet its tooth structure — its upper sectorial * — is exceptional in a way 
peculiarly its own. Neither Cyncelurus, therefore, nor its extinct 
ally JElurodon, seems to help us towards tracing the cat's pedigree. 

The flat-headed cat (F planlccps), as has been shown (Fig. 177), 
approximates somewhat towards viverrine forms in the large size of 
its two-rooted first upper molar. But the extinct genera Pseudcelurus, 
Dinictis, and above all, Arc/ice turns, lead us decidedly towards more 
generalized forms, and render the descent of both Cryptoprocta and 
Fells from some common Viverrine root a matter highly probable. 

It must be borne in mind, however, that although these miocene 
and eocene cats were thus generalized in structure, yet a most ex- 
tremely specialized form of cat, e.g., Eusmlhis, existed at the same 
early period. But a very generalized kind of dog, Otocyon (which has 
four premolars and three molars on either side of each jaw), exists 
to-day side by side with dogs in which the number of teeth is much 
less, and which are more specialized. Yet naturalists do not on that 
account doubt but that Otocyon is a survivor of an earlier condition 
once common to the whole group of Cynoidea. Similarly the co- 
existence of Fusmllus with Dinictis or Arch celur us, does not detract 
from the probability that in the last two genera we have examples of 
the sort of animals whence all cats come. 

Zoological and pal aeontological evidence, then, points to a viverrine 
origin of cats. They seem either to be the very specialised descend- 
ants of ancient viverrine animals, or else both cats and viverrines are 
the diverging descendants of an ancient, more generalized form 
which existed in times anterior to the eocene, of which more gene- 
ralized form no relics have as yet been discovered. 

§ 4. But the viverrine animals themselves, whence came they ? 
In the existing creation, they are distinguished from the hyaenas by 
having two upper tubercular molars. But Professor Gaudry has 
discovered a form (named by him Ictitherium hlpparlonum, which, 
as we have seen,f is intermediate between the civets and hyaenas, 

* See ante, p. 428. f See ante, p. 507. 

L L 



514 



THE CAT. 



[chap. XV. 



and which, though it has two upper tubercular molars, has the 
hinder one quite rudimentary.* 

The civets, again, differ from the hysenas, in having a lower 
tubercular molar. Bat the same accomplished palaeontologist has 
discovered another fossil form, Hymnictisrf which is hyaena-like, but 
yet has a rudimentary lower tubercular molar tooth. 

But can we get any probable suggestion as to the origin of the 
cat's sub- order, the JEluroidea? To be able at all to answer this 
question, we must glance at fossil forms related to the other car- 
nivorous sub-orders. As regards the dogs (Cynoidea), the existing 
Otocyon, and the fossil genus Galecynus,% lead down to forms of more 
general affinities which may have been dog ancestors. One such 
is Cynodictis § (of the upper eocene), and which leads on to Cynodon,\\ 
which is a still more generalized form, showing, in M. Gaudry's 
opinion, certain affinities to the civets. 

Amongst the Arctoidea,the weasel family (Mustelidce) is — inasmuch 
as it is an arctoid family — distinguished by a variety of characters IT 
from the Viverridw. Amongst the characters by which it differs is 
that of the absence of a second upper tubercular molar. InLutyictis** 
however, we have a musteline form in which the second upper 
tubercular molar is present, though very small. ff ln.PrcceluruS)%% 
also, we have a fossil with seeming musteline and viverrine affinities, 
yet with teeth which approximate to those of the cats. The true 
bears (Ursidcp) were preceded by mammals such as the miocene 
Hyce-narcto8 y §% which, with the help of Amphicyon,\\\\ apparently 
connects them with the dogs. 

The three sub- orders of carnivora being thus brought near to- 
gether in the past, to what other group can they — i.e., can the 
whole order Carnivora — be affiliated ? What may probably have 
been the cat's ancestors in a yet more remote degree than the un- 
known common stock whence the three existing suborders gradually 
diverged ? 

§ 5. We have seen ^[ that the oldest tertiary mammal Arctocyon, 
has characters which give it some claim to be nearly allied to the 
progenitor of all true carnivora. But besides such characters, we 
find in it conspicuous defects of palatal ossification, and a low form 
cf brain, which characters would seem to make it impossible that its 
claim to be an ancestor of the carnivora should be established. 
Moreover, we have seen that there are a number of eocene fossils 
such as Ptcrodon, Proviverra, Hycenodon, Palceonyctis, &c.,*** which 
agree in having (amongst other common characters) teeth which are 
not differentiated into premolars and an upper and lower sectorial 

* See Les Enchainements, p. 217, 
fig. 286. 

t L. c, p. 218, fig. 289. 

X See ante, p. 507. 

§ See ante, p. 50. 

|| See Les Enchainements, p. 215, 
figs. 282 and 283. 

f Ante, p. 475. 

** See ante, p. 507. 



*rf See Les Enchainements, p. 219, 
fig. 290. 

XX See ante, p. 435. 

§§ See ante, p. 507, and Les Enchaine- 
ments, pp. 212 and 213, figs. 278 and 279. 

|| || See ante, p. 507, and Les Enchaine- 
ments, p. 212, fig. 277. 

f f See ante, p. 506. 

*** See ante, p. 505. 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 515 

tooth followed by one or more tubercular molars, but which, instead 
of this, had a series of sectorial teeth. 

§ 6 It has been contended by several eminent palaeontologists 
that these creatures were marsupial, and that all the first mammals 
were didelphous mammals — an opinion supported by the before 
explained * resemblance of the mesozoic mammalian fossils to the 
existing marsupial — Myrmecobins. 

If this view is correct, the pedigree of the cat descends through 
marsupial ancestors to the most generalized placental (or monodel- 
phous) carnivora. It is here contended, however, that such was 
not the case, but, on the contrary, that it is probable that the cat 
never had a marsupial (or didelphous) ancestor at all, but that its 
progenitors (anterior to carnivores) were long-lost beasts of the 
Order Insectivora. It appears indeed to be probable that Insectivores 
and not Marsupials were the parent forms of the great Mammalian 
stock — i.h, that the hedgehog and not the opossum is the existing 
representative of the root-form of that class to which we (as 
animals) and the cat both -belong. 

Those characters in which Pterodon, Proviverra, Hymnodon, Pake- 
onictis, &c, have been thought to resemble marsupials, tell equally 
in favpur of their affinity to the Insectivora. Such are the small 
brain, with uncovered corpora quadrigemina and large olfactory lobes 
— characters wjiich has been shown to have existed in Proviverraf 
and Arctocyon.% Such again are the numerous sectorial teeth of 
Hycenodon, Pterodon, Palceonictis, Proviverra and others, and the 
defective palatal ossification of Arctocyon. Moreover these forms 
do not possess more than six incisors above and below, while tbe 
angle of the mandible is not inflected. If the angle were inflected, 
however, such a character would not be decisive in favour of their 
marsupial affinities, as the Taurec (Centetes), though a placental 
mammal — a member, moreover, of the order Insectivora — has 
its mandibular angle inflected. Hycenodon and Pterodon have also 
been shown § to have possessed a complete milk dentition, a character 
which separates them markedly from all existing marsupials. 

To this reasoning it may be replied, that true marsupials existed 
in Europe contemporaneously with the beasts the nature of which 
is in dispute, and that the earliest known mammalian remains 
(those of the secondary rocks) resemble existing marsupials. These 
assertions are true, but in the first place the existence of marsupials, 
with such creatures as Proviverra, only proves that marsupial life 
was then already developed as well as placental life, a fact 
of which we have abundant evidence. || Such a fact, however, 
in no way shows that the latter was derived from the former. 
Then as to the mesozoic mammals, the forms now living which they 
resemble, i.e., Myrmecobius, is just one of those marsupials to which 



* See ante, p. 504. 

+ See Les Enchaiiiements, p. 21, fig. 
15. 

$ See P. Gervais, in Nouv. Arclriv. 
du Museum, vol. vi., 1870, p. 147, plate 



6, fig. 4. 

§ By M. Filhol, see Ann. des Sc. 
Geologiques, vol. vii., p. 169, plate 22, 
fig. 79, and plate 31, fig. 148, 1876. 

|| See ante, p. 507. 

L L 2 



516 THE CAT. [chap. xv. 

the specially marsupial character, " the pouch," is wanting. The 
same is the case in the allied genus Phascogale, while in most of the 
small American opossums (Didelpht/s), the pouch is not developed. 
The character is still a very variable one in many forms of the order — 
as if it had not become even now a well-established character. In 
the predatory opossum — the so-called Tasmanian wolf (Thylacimis), 
" the marsupial structure, if shown at all, is represented by a .pair 
of shallow, semi-lunar fossae, with their concave outlets opposite 
each other as in Echidna." * 

It is the very highly specialized Australian kangaroos and pha- 
langers — forms which may be relatively modern developments — 
which have the pouch most completely formed and which may be 
considered the typical representatives of marsupial life. 

Moreover the secondary fossils, Amphithorium, Amphikstes, Dro- 
matherium and Phascolotherium, had, as we have seen,f but six 
incisors in the mandible, while only in Phascolotherium was the 
mandibular angle inflected. All then that the yet discovered meso- 
zoic fossils can be held to demonstrate is, that there existed at the 
time of their entombment, forms having both placental and didel- 
phous affinities and which may have been some of the as yet 
undifferentiated ancestors whence those two now divergent sub- 
classes of mammals have descended. 

And it is far from impossible that some existing marsupials may have 
come from a different root from that which gave rise to others. Forms 
may have grown alike from different origins, as few things are more 
certain in the matter of development, than that similar structures 
often arise independently, and causes which would induce marsupial 
modifications in the descendants of one root-form might well also 
induce them in those of another root-form. The singular difference 
in the structure of the hind-paw in the more typical marsupials — 
the kangaroos and phalangers — from that which is found in Didelphys, 
Dasyurus, Phascogale and 3Iyrmecobius, seem to point to a twofold 
origin of the modern order Marsupialia. The hypothesis then 
which represents the most ancient mammals to have been allied to 
the Insectivora, is one which appears to me best to accord with all 
the facts yet known. Thus we may account for the low brain 
structure and defective palate of Arctocyon ; for the form of the 
molars of Proviverra and its allies ; for the form of the astragalus 
noted by Professor Cope ; for the number of the inferior incisors ; 
for the rare inflection of the mandibular angle and for the existence 
of a complete milk dentition. 

From this Insectivorous root then, the Marsupials, as we at 
present know them, must have diverged as a relatively unimportant 
branch, while the main stem of the mammalian tree was continued 
on by the successively arising placental forms of life. It seems far 
more likely that the allantois came to atrophy and the pouch to be 
developed, and that so the modern marsupial structure was initiated ; 

* So says Professor Owen, Philoso- i t See ante, p. 504. 
phical Transactions, 1865, p. 676. 1 



chap, xv.] TEE PEDIGREE AND ORIGIN OF THE CAT. 



517 



than that the allantois should first appear as a functionless rudi- 
ment. It also seems more probable that the habit of forming milk 
teeth is one which has been lost or almost lost in certain mammals, 
than that the process should first have arisen through the replace- 
ment of a single, relatively unimportant, tooth, by a vertical successor 
to it — a condition which has been found* to be the case in the 
marsupials of our own day. 

§ 7. The succession of mammalian carnivorous life — the mammalian 
portion of the cat's pedigree — may then be represented as follows : — 

From unknown Insectivora-like mammals, two diverging series of 
forms may have started, one soon leading to Arctocyon (as the 
Insectivora-like root of the placental Carnivora), the other series 
developing such forms as Proviverra, Hycenodon, and Pterodon, and 
continuing on the main stem through Grymnura-like creatures to the 
modern Insect icora. From this insectivorous stem we may imagine 
a side-shoot to be given off leading through Palceonictis to forms 
like certain existing marsupials, and diverging into the American 
Didelphys and the analogous Australian Dasyurus. From Arctocyon 
we may conceive the great carnivorous branch — destined to quite 
surpass and overshadow the insectivorous stem — to divide into 
cynoid and arctoid branches. The former continuing on through 
Cynodon and Cynodictis, would lead up through Gcdecynus and 
forms like the existing Otocyon to the typical Canidce. The great 
arctoid branch may have given off a limb leading through Ampliicyon y 
Hycenarctos and kindred forms, to the existing Ursidce, and then 
continued on through Procehirns and Lutrictis, as the Mustelidce. 
From some such form as Procelurus the great -ZEluroid sub-order 
may have started, and before continuing on, as the Viverridw, have 
given off a great branch to be developed, by bifurcating, into the 
HycenidceyCryptoproctidce and Felicia?. The first family is the culmina- 
tion of one division which passes through IctitJieruim, and which 
gives off Proteles as a one-sided branchlet. The other division into 
which the ^Eluroid branch bifurcates, continues on as the cats, first 
giving off however, near the bifurcation, the branchlet ending in 
Cryptoprocta. The proper felme branch then continues on through 
Arc/uel/rrus, Dinictis, Nimravus and Pseudceluriis, and then bifurcates. 
It ends in the typical genus Felis on one side — an aberrant twig 
being given off for Cyncelurus — while on the other side it continues 
on though Hoplophoneas, Pogonodon and Machcerodus f to the very 
specialized aberrant form Eusmilus* 

This hypothetical genealogy is only offered as a speculation, especi- 
ally that part of it which represents conditions anterior to the evolution 
of the viverrine branch. It reposes mainly upon dental characters, 
and teeth are organs which not only might be expected to vary with 



* By Professor Flower. See his paper 
in the Philosophical Transactions, vol. 
clvii., 1867, p. 631. 

+ The small lamina of bone which em- 
braces the external carotid and so forms 



the "ali-sphenoid canal " may well have 
independently disappeared and again, by 
reversion, reappeared in either sub- 
division of the feline branch. 



518 



THE CAT 



[CHAP. XV. 



varying conditions of life, but which, we know to be sometimes very 
differently formed in different members of one and the same family. 
Yet we must accept their evidence or none. It is the only evidence 
which is largely available, nor will there be much danger of serious 
error in making use of it, if the caution here offered as to its defec- 
tive nature be duly borne in mind. 



Felis. 



MaehseYrodus. 

PogoiAodon. 
HoploplioneXus. / Cynadurus. 



Pseud 



Ir.seciivora, 



Cryptoprocta 



Viverrida3, 




§ 8. If we can only conjecture with more or less probability what 
were the older mammalian ancestors of the cat, we are still less able 
to determine the line of its descent through non- mammalian ances- 
tors. The structure of the shoulder girdle of the Monotremes, may 
be held to point towards a reptilian origin of the Mammalia ; but 
the position of the ankle-joint and the constant development in 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 519 

every species of two occipital condyles rather indicate a Batrachian 
ancestry. On the whole it seems probable that the Mammalia, and 
therefore the .Cat, descended from some highly- developed, somewhat 
Reptile-like, Batrachian, of which no trace has yet been found. The 
yet more remote ancestor of such Batrachian will have to be sought 
amongst extinct and unknown fishes, intermediate between Ganoids 
and Elasmobranchs, but with considerable fundamental affinity to the 
Eays, however different from them they may have been in external 
aspect. Beyond this point no suggestion worth making can be 
offered. The genetic relations of the Tunicates and the Vertebrates, 
or between either of these and any worms intermediate between 
Tunicates and Yertebrates, which may have existed, cannot be 
spoken of as even probably known. 

§ 9. The foregoing suggestions are offered as results which seem 
to present themselves to the inquirer into the past history of 
animal life, and into the cat's pedigree. 

The next question refers to the cat's origin. This second 
question refers, as before said, to the probable causes which have 
determined that process of evolution which has, in fact,, taken 
place. It is a question of causation : It investigates the " how " 
and the "why " of the origin of the cat's species, and — as we 
cannot suppose that the cat is different in this respect from other 
animals — the cause of the origin of species generally. Evidently 
that cause must lie either within ' or without the living organisms 
which are evolved, unless it be partly within them and partly 
external to them. 

We may conceive the evolution of new specific forms to have 
been brought about in one or other of the six following ways. 
The change may have been due : — 

(1) Entirely to the action of surrounding agencies upon organ- 

isms which have merely a passive capacity for being 
indefinitely varied in all directions, but which have no 
positive inherent tendencies to change or vary, whether 
definitely or indefinitely ; 

(2) Entirely to innate tendencies in each organism to change in 

certain directions ; 

(3) Partly to innate tendencies to vary indefinitely in all direc- 

tions, and partly to limiting tendencies of surrounding 
conditions, which check variations except in such direc- 
tions as may happen to be accidentally favourable to the 
organisms which vary ; 

(4) Partly to innate tendencies to vary indefinitely in all direc- 

tions, and partly to external influences which not only 
limit but actively stimulate and promote variation ; 

(5) Partly to tendencies, inherent in organisms, to change defi- 

nitely in certain directions, and partly to external 
influences acting only by restriction and limitation on 
variation ; 

(6) Partly to innate tendencies to change definitely in certain 



520 THE CAT. [chap, xv 

directions, and partly to external influences which, in 
some respects act restrictively, and in other respects act 
as a stimulus to transformation. 

The writer has elsewhere * stated at length his reasons for con- 
cluding that the genesis of new species is due mainly to an 
internal cause, which may he stimulated and aided, or may be 
more or less restricted, by the action of surrounding conditions. 

The notion that the origin of species is due to " Natural Selec- 
tion " is a crude and inadequate conception which has been welcomed 
by many persons on account of its apparent simplicity, and has 
been eagerly accepted by others on account of its supposed fatal 
effects on a belief in Divine creation. 

Its anti-theological character has been declared by a conspicuous 
English advocate, to be " one of its greatest merits," while it has 
been made use of as a fandamental dogma in the various polemical 
works of Professor Haeckel. 

The present author's views as to "Natural Selection" having been 
already fully expressed in former works, it is not thought necessary 
that farther space should here be occupied by their repetition. 

§ 10. Before entering upon the question of " Origin," a few 
words of preliminary explanation seem to be needed. Obviously 
before we can enter profitably upon the discussion of any pro- 
position, we must clearly understand its terms, and it would be a 
useless task to discuss the origin of anything as to the very 
existence of which we may have reason to doubt. 

Before enquiring into the origin of species, it will be well to 
make sure what we mean by a " species," and that there really 
is any such thing. 

We have to consider the origin of the cat, as a " species " of 
the genus Fells, of the family Felidce. What then is a " species," 
what a "genus," and what a "family?" Who has ever seen or 
handled one of these entities ? Individual cats and cat-like creatures 
of various kinds abound, but no one pretends to have anywhere 
met with a "family " or a " genus." Why then should a " species" 
be spoken of as if it had more reality in it than they ? In fact it 
has just as much and no more reality than they have. A " species,'' 
like a "genus," or a "family," or an "order," or a "class," is an 
idea ; and its existence, as a species, is only ideal. 

Has it then no reality whatever? Undoubtedly it has. A species 
is real, inasmuch as any individual animals actually have in the 
concrete those very characters and powers which exist abstractedly 
in the idea of the species. It is just the same with every " genus," 
"family," "order," and "class." Each and all of these are "real," 
inasmuch as the abstract ideas they nay severally refer to, are 
concretely embodied in numerically separate and distinct, individual, 
material, living creatures. 

* See the "Genesis of Species," and also Chapters YIII., IX., X., and XIV., of 
"Lessons from Nature." 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT 521 

To seek, then, the genesis of species, as species, would he to in- 
vestigate the origin of certain ideas. But that would not he at all 
the object here pursued. That object is 'to enquire how it is that a 
certain concrete entity (a certain animal, which is the living 
embodiment of one idea) gives rise to another concrete entity — 
which is the living embodiment of a different idea. 

§ 11. Now all our knowledge being derived from experience, we 
can only (revelation apart) judge of things as they have been, by 
things as? they are ; and as every animal is now the product of a 
parent organism more or less like it, so the natural inference with 
regard to any antecedent animal, is that it also was the product of 
a parent organism more or less like it, 

But it may be said : " this analogy does not apply to the embodi- 
ment of a new species, because " (it may be asserted) " we never see 
the origin of such an embodiment — we never see anything like a 
change of species : we cannot, therefore, from our present experience, 
even guess what may have been the mode of appearance of a con- 
crete entity embodying an idea different from that embodied .by the 
entity which preceded it." 

This assertion, however, is here denied, while it is on the contrary 
affirmed that we do see — as far as human eye ever can see or ever 
could have seen — the origin of concrete embodiments of ideas which 
are not only as distinct as one species from another, but as distinct 
as genera, families, orders, classes, and even kingdoms, one from 
another. It is also here contended that we may see this daily, even 
in the case of the cat. 

It was this consideration — an anticipation of the argument here 
to be advanced — which caused the facts, and the significance of the 
facts, of the cat's embryonic development to have been so dwelt 
upon, as they have been in the tenth chapter of this book. For the 
incipient embryo of the cat, is no cat : it is not even an animal. Its 
existence is merely vegetal, and the successive ideas which it em- 
bodies (in the course of its evolution) approximate only by degrees to 
that embodied by the adult animal. The embryo which is to become 
a cat, successively embodies ideas which are analogous to, though 
they are never identical with, those which are manifested in rhizo- 
pods, sponges, worms, fishes, batrachians and other inferior animal 
natures. We see these changes as facts ; the actual " how," the 
intimate mode in which the living idea or form, is embodied in and 
identified with the matter it informs, is one of those impenetrable 
secrets of nature for ever closed to human ken, as the mode in which 
— the actual " how " — the mind is enabled to know itself and 
things external to it, is closed to human ken. None the less, every- 
one who admits that the living cat when adult is informed by a 
psychical principle of individuation, may be called upon also to admit 
that its developing embryo is successively informed by psychical 
principles of individuation of different orders — orders which present 
no trifling analogy to different orders of animals which exist perma- 
nently. After the true cat form has been once attained, such changes 



522 



THE CAT. 



[chap. XV. 



cease, and, till death, the cat remains a cat simply. With death, 
however, the process of change recommences (though it is a very 
different process), and continues during the gradual recession of all 
those forms which have any relation to life, till the hody is reduced 
to mere inorganic matter. 

§ 12. According to our present experience then, we ought to 
anticipate that any new ideal embodiment — any new specific form— • 
would make its appearance during the period of embryonic life, and 
that if a new- cat-species is to appear, it will appear as a kitten 
which differs more or less markedly from its parents. Such a birth 
is by no means against experience. It is not merely that minute 
changes occur — no two individual animals being absolutely alike — 
but every now and then a marked variation takes place, as in the 
case of the kitten seen by Mr, Birkett.* Such variations also are 
capable of being transmitted to the offspring cf the animals in which 
they first arise. 

But we may even gather some evidence in favour of the origin of 
species by considerable and not minute changes, from the special 
subject of this work— the group of Cats. Species of Machcerodus, like 
Smilodon, were, as we have seen,f unable to kill by biting on 
account of the enormous length of their upper canines, which could 
only be used as daggers, the mouth being closed. All existing 
feline animals, including the long-tailed, clouded tiger (F. macrocelis), 
bite, and are unable to use their canines as daggers. Now, if the 
canines of Machcerodus Smilodon had been formed by minute increase 
in successive generations, the creatures would at one time have been 
in a condition such that their teeth were too long to be conveniently 
used for biting, while they were not yet long enough to be efficiently 
used as daggers. It is true that there are different species of 
Mac/icerodus with teeth of very different lengths, and it is also true 
that before the canines became so long as to be quite useless for 
biting, they would begin to be slightly useful as daggers. Still the 
fact remains that a highly inconvenient transitional stage of exist- 
ence i must have been passed through, if evolutionary changes were 



* See ante, p. 7. Amongst new organic 
forms known to have been suddenly 
evolved are : The black -shouldered pea- 
cock, new forms of wild deer, a smooth 
capsuled kind of Datura tatula, a com- 
plex-capsuled form of poppy, &c, &c. 

+ See ante, p. 432. 

% Professor Cope has said (see Pro- 
ceedings of the Acad, of Nat. Sc. of 
Philadelphia for July 8, 1879):— "I 
think there can be no doubt that the 
huge canines in the Smilodon s must 
have prevented the biting off of flesh 
from large pieces, so as to greatly inter- 
fere with feeding. . . . The size of the 
canines is such as to prevent their use as 
cutting instruments, excepting with the 
mouth closed, for the latter could not 



have been opened sufficiently to allow 
any object to enter it from the front. 
Even were it opened so far as to allow 
the mandible to pass behind the apices 
of the canines, there would appear to be 
some risk of the latter's becoming caught 
on the point of one or the other canine." 
As to the cause of the disappearance of 
this highly specialized form of life, Pro- 
fessor Flower has observed (in a lecture 
delivered at the Eoyal Institution on 
March 10, 1876) : — "It may have been 
a case of over-specialization, in which 
the development of the carnivorous type 
of dentition, gradually accumulating in 
intensity . . . , became at last a succes- 
sive inheritance so exaggerated that its 
growth outran its usefulness of purpose. 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 



523 



always minute changes. If, however, a sudden and considerable 
change took place, this difficulty, in the way of evolution, would be 
completely evaded. But what is here said of Machcerodus, has a 
wide application. Were not forms of life evolved by a process which, 
compared with their duration, is "sudden," the world would be a 
zoological chaos. But such is not the case. A multitude of un- 
doubtedly stable and plainly distinct kinds exist now, and thence 
we may conclude that stable and distinct kinds always existed, how- 
ever difficult the definition of some forms may be in certain cases. 

Returning from this digression to the question as to the mode of 
individual development and evolution, if we extend our view beyond 
the class of mammals, far more striking phenomena will present 
themselves to our notice than any with which we have become 
acquainted in studying the development of the cat. Thus in the 
development of such an animal as the frog, we find that two 
remarkable transformations take place. One of these is the trans- 
formation of the egg into a fish-like tadpole, the other is the 
transformation of the tadpole into the frog. In that singular species 
of Mexican eft, the axolotl, we find that a few individuals will every 
now and then (under the stimulus of certain conditions of their 
environment) quickly undergo a transformation, not merely of 
external appearance, but one which affects their very skeleton, and 
changes the distribution of the teeth in their jaws. In insects, as 
e.g,, in- the butterfly, we have the well-known marvellous meta- 
morphosis which is effected during the period of its existence as a 
quiescent chrysalis. Other lowly animals undergo still more sur- 
prising changes, which in many of them, as in the Tunicates, may 
lesult in the production of an adult form which is of a lower order of 
organization than that of the transient being which served to evolve 
it. Such facts as these show how probable it is, that at various 
different stages of individual evolution, sudden changes caused by an 
acceleration or by an arrest of the development process, or even by 
some retrogressive action, may have resulted not merely in the 
production in the concrete of new species, but even of a new genus, 
a new family, or a new order ; for we see equivalent changes going 
on before our eyes now.* 



. . . Such appears to be constantly the 
fate of forms which have become over- 
specialized, or in which the development 
of one part has run on in one particular 
direction out of due proportion to the 
rest of the organization. We know that 
it is- quite possible, by artificial selection, 
to produce animals with one particular 
part developed even detrimentally to the 
entire economy of the creature, and it 
really seems as if something of the same 
kind not unfrequently occurs in nature." 
It is indeed true that for the perfection 
of any living creature there is need of 
harmony between its various powers, 
and a moral may be drawn from the 



above instance as to the dangers likely 
to result to any race of mankind from a 
one-sided, ill- balanced development of 
those intellectual powers which give man 
supremacy over all lower forms of life. 

* Some readers may feel a difficulty in 
accepting the view here put forward (as 
to the serial succession of different 
psychical principles of individuation in 
the development of each individual 
animal such as the cat, frog, or butterfly), 
on account of the gradual mode in which 
even rapid metamorphoses take place. 

The tadpole only by degrees becomes a 
frog, and gradual processes of change 
take place within the seemingly quies- 



524 



THE CAT 



fCHAP. XV. 



§ 13. It may be said that we even see the fresh starting forth of 
life itself. In many plants, the ovule (after developing to that extent 
which is its condition in the fully formed seed) ceases to be active. 
The seed is shed and dies. But on the occurrence of the requisite con- 
ditions, it lives again and comes rapidly to manifest a new psychical 
principle of individuation altogether different from that which informed 
the same matter when it was a developing seed. It may, perhaps, 
be objected by some persons that : "if the seed is not actually living 
during its period of quiescence, the result shows that it has neverthe- 
less been potentially alive." But it is impossible to understand how 
anything can be really " alive " when all vital activity is really 
absent, and no such activity can be affirmed to exist during the long 
periods * in which dry seeds may be preserved without decomposi- 
tion. The " vital activity " of a seed is " germination." 

As to " potential life," its existence may be freely conceded ; but 
potential "life" is actual "deatb." The "potentiality" is not in the 
seed merely, but in the environing conditions and external stimuli 
also, yet "life" is not to be predicated of such "conditions" and 
" stimuli." The dead seed is but a piece of matter so appropriately 
formed that if it and other matters are brought together under certain 
conditions, a new living being results from the conjunction. This is 
but a case of that genetic activity which all persons who believe that 
life first arose spontaneously in the world, must admit to have once 
existed, and if " once," why not " always ? " 

§ 14. But how are all the changes of development in the cat, and 
in all animals and plants, carried on ? Is it by a number of fortuitous 



cent chrysalis. It may be asked then : 
How can a new "form " suddenly arise, 
when the body it informs arises gradu- 
ally ? But are not a piece of oak, and 
woodashes, different substances ? Yet 
does not fire gradually effect the trans- 
formation of the former into the latter ? 

Our organs of sense are indeed so con- 
structed and so act that they are in- 
capable of positively seeing any absolute 
commencement whatever. When we seem 
to perceive such a thing (as, e.g., in the 
explosion of gunpowder), the apparent 
absolute suddenness is but due to the fact 
that the gradual changes which really 
take place are too minute and too rapid 
for our sense-organs to follow. There 
can be no doubt but that if our powers 
of sense were in these respects greatly 
augmented, an explosion of gunpowder 
would then be seen by us to be a gradual 
process. 

But the emergence of a new psychical 
principle of individuation is a thing 
which is and must ever remain essentially 
imperceptible to our senses, however much 
their powers might be augmented. Each 
such psychical principle can — as we 
know by our own personal experience — 



continue to inform a body while that 
body undergoes various changes and 
gradual modifications within certain 
limits ; but will cease so to exist when 
once those limits are passed. The actual 
amount of change which the body of a 
developing animal can undergo while 
informed by any one principle, and the 
physical conditions which determine the 
lapse into potentiality of that principle 
and the advent of another, may ever 
remain a matter of speculation only. 
There appears, however, to be evidence 
that such changes actually take place, 
and the gradual preparation of the living 
matter for their occurrence is a phenome- 
non which harmonizes with our experience 
as to the only psychical principle of in- 
dividuation of which we have any 
thorough knowledge — our own. 

* Mr. Carruthers, F.R.S., has kindly 
informed me that seeds of Nelumbium 
(a beautiful aquatic plant belonging to 
the Lotus group) have germinated after 
having been preserved in the British 
Museum for upwards of a hundred years. 
In this case it is manifest that all vital 
activity was for a very long time really 
absent. 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 525 

changes, and by phenomena without order, and apparently subject 
to nu law ? Surely it is the very reverse ! The transformations, 
the successive embodiments of new ideas of all ranks and degrees, 
which are daily taking place in countless myriads on all sides of us, take 
place harmoniously and in due order. However singular or surprising 
may be the process of evolution in certain cases, however round- 
about its course, or unexpected its intermediate stages and ultimate 
outcome, it is in each and every case a process carried on according 
to definite internal laws to fulfil a precise * and predetermined end. 

What we find to be the case now, we ought, if we are to take 
experience as our guide, to regard as having been the case ante- 
cedently. Thus the process of specific evolution in the past will 
have been no process effected by a fortuitous concourse of influences, 
or by minute haphazard variations in all directions, but by a definite 
system of internal law, aided and influenced in the past as it is 
aided and influenced now, by the action of incident forces, also 
operating according to law, and resulting in due and orderly " specific 
genesis" 

§ 15 The idea of an internal force is a conception which we 
cannot escape if we would adhere to the teaching of Nature. If, in 
order to escape it, we were to consent to regard the instincts of 
animals as exclusively due to the conjoint action of their environ- 
ment and their physical needs, to what should we attribute the 
origin of their physical needs — their desire for food and safety, and 
their sexual instincts ? If, for argument's sake, we were to grant 
that these needs were the mere result of the active powers of the 
cells which compose their tissues, the question but returns — whence 
had these cells their active powers, their aptitudes and needs? 
And if, by a still more absurd concession, we should grant that these 
needs and aptitudes are the mere outcome of the physical properties' 
of their ultimate material constituents, the question still again 
returns, and with redoubled force. That the actual world we see 
about us should ever have been possible, its very first elements 
must have possessed those definite, essential natures, and have had 
implanted in them those internal laws and innate powers which 
reason declares to be necessary to account for the subsequent out- 
come. "We must then, after all, concede at the end as much as we 
need have conceded at the outset of the inquiry. 

Potent amongst the agents operating in the process of specific 
evolution must be that internal, individual, psychical force — that soul 
or psyche — which we have seen reason postulates as the most 
important, though invisible, constituent of every concrete living whole. 
It must play this predominant part, because it is by its action that 
the whole multitudinous and diverse processes of life are co-ordinated 



* Some persons may think that the 
occurrence of monstrous births, &c, con- 
stitutes an objection to the above state- 
ment. Xo one however imagines that 
the fact of a man becomiug lame through 



some accident is in contradiction with 
the harmony of Nature's laws. But an 
accident occurring before birth is no 
more in contradiction with such harmony 
than is an accident to an adult. 



526 



THE CAT. 



[chap. XV. 



and controlled into that unity which, we perceive in each separate 
living organism. 

All nutrition, growth, and reproduction are normally controlled 
and ultimately effected by it, no less than all motion, feeling, and 
cognition. Therefore it is by it that those physical changes are 
effected which, during the process of individual development, so 
change the conditions of the matter of the body, as, by degrees, to 
render it unsuitable for the form actually embodied in it, and to 
prepare it to receive that form which comes next in the order of 
evolution. 

§ 16. This is what is really meant by the assertion that the 
genesis of species takes place mainly through the agency of an 
internal force,* and this mode of origin may — as opposed to the 
hypothesis of natural selection— be fitly termed P3YCHOGENESIS. 

§ 17. But the farther question may yet be asked, what de- 
termines the origin of species by psychogenesis ? What controls 
and directs the successive evolutions and disappearances of these 
various " forms " or psychical principles of individuation — " forms " 
which ever arise in due order and succession now, and which we 
may therefore infer to have arisen in due order and succession 
through the countless ages of past organic activity ? 

To this question no reply is possible without passing from questions 
of physical science to the highest problems of philosophy . But no 
natural object can be fully understood without reference to such 
problems, and to shrink from explicitly referring to them here, 
would be a dereliction of scientific duty, The consideration of the 
action and nature of no cause which there is reason to suppose 
influences the formation of living creatures, can fitly be omitted 
from the study of the evolution of any form of life. 

The observer of nature who contents himself with considering 
external phenomena and does not reflect on his own intellectual 
powers and the similar powers of his fellow-men — such a partial 
observer of nature may perhaps conceive of the cause thus operating 
in evolution as unintelligent. He may deem it to be some principle 
utterly inconceivable by us, pervading all space and enduring 
through all time, yet devoid of consciousness and will. He may 
deem it to be a force incapable of apprehending what it produces, 
but which is at the same time the origin of all law, all beauty, and 
all intelligence. 

But let us see what such a conception really means. It is 
admitted that we cannot transcend experience. We cannot then 
imagine a first cause save in terms the elements of which are within 



* This conception, pnt forward in 
"The Genesis of Species," seems to be 
now practically admitted, even by the 
author of "The Origin of Species," for 
the latter has come to admit that "abrupt, 
strongly marked changes," may occur 
"neither beneficial nor injurious " to the 
creature which exhibits them, produced 



by "unknown agencies" lying deep in 
" the nature of the organism/" It is 
hardly necessary to point out that with 
respect to such developments, "Natural 
Selection " must be absolutely impotent. 
Upon such chaiiges it cannot possibly 
exert any influence whatever. 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 527 

that experience. Now tlie highest entities thus known to us are 
human intellect and human will. Besides these, we know only the 
merely animal, the vegetal, and the inorganic worlds. Should 
we then imagine the Universal First Cause in terms of some gas or 
some merely physical force? Such a conception has but to be 
stated to show its absurdity. But if we attribute to the Great Cause, 
active in organic nature, an activity wdiich is intelligent in its 
results, but not in itself — not in the agency which produces those 
results — we thereby attribute to it a sort of instinct, and, in order to 
avoid the error of anthropomorphism, we fall into the vastly greater, 
and more absurd, error of zoomorphism ! 

We have no choice, then, but to imagine this Great Cause in 
terms derived from human nature while confessing their inadequacy 
and being careful to render 1 them as little inadequate as is possible, 
by considering all that is positive in them as raised to infinity, and 
at the same time eliminating from the conception all that is negative 
and imperfect. 

When, however, extending our view over the whole of Nature, 
we 'include in our study man's faculty of apprehending truth, good- 
ness, and beauty, together with his wonderful power of occasionally 
controlling by his free will his own thoughts, desires, and actions, and 
so actively intervening in the chain of physical causation, the idea of 
the first cause as God becomes evident to the mind ; nor can it be 
rejected without self-stultification. The denial of the validity of 
this inference involves a negation of facts and of intellectual prin- 
ciples, which negation carried out to its logical consequences destroys 
itself by the sceptical destruction of those very premises on which 
that denial must itself repose. 

The philosopber then has the strongest possible ground for affirm- 
ing (in reply to the question as to the cause of Psychogenesis) that 
in the process of evolution we have evidence of the activity of a 
Great First Cause, ever and always operating tbroughout nature in 
a manner hidden indeed from the eye of sense, but clearly mani- 
fested to the intellectual vision of every unprejudiced mind. This 
action is that secondary or derivative creation,* "per temporum 
moras" distinguished by St. Augustine, from that instantaneous 
primary creation which took place, " potentiaUter atque causaliter," 
in the beginning. Thus a belief in " evolution " far from leading to 
a denial of " creation," distinctly affirms it. 

Indeed the candid study even of merely organic life makes 
evident the logical need which exists for the Theistic conception. 
The course of individual development as it goes on in every kitten, 
shows the existence of a final, no less than of an efficient cause of 
the developmental process. Anyone who would pretend that the 
mere conflict of independent efficient causes can produce a co-ordi- 
nated series of effects, resulting in the attainment of a definite end, 
which they have all concurred to produce, would certainly go against 

* See "Lessons from Nature," p. 429. 



528 THE GAT. [chap. xv. 

all our experience. Airyone, also, who should pretend that we cannot 
affirm a " purpose " to exist in different natural processes (i.e., who 
denies that we can assert a " final cause " for any phenomenon) 
because we are unable to state the final cause of the whole series of 
physical phenomena, would be like a soldier who, because he was 
ignorant of the plan of campaign of his commander-in-chief, should 
pretend that therefore he could not infer that commander's purpose 
in sending medical stores to the military hospital. 

The co-operation of a variety of actions under complex conditions 
in the production of something which works well and which is the 
admirable practical result of their harmonious co-operation, supposes, 
as our experience shows, a cause in which that future phenomenon 
is ideally represented ; and the more complex the conditions, and 
the more numerous the actions may be, the more certainly may the 
conclusion be drawn that such prevision existed. 

The Theistic idea once accepted, how does the action imminent in 
nature accord with our idea of God, thus conceived ? 

Surely it is just that sort of action which was to be expected. It 
is an action which harmonises with man's reason, which is orderly, 
constant, and universal, yet which ever eludes our grasp, and is 
effected by ways and in modes very different from those by which 
we should have attempted to accomplish such ends. 

As to "creative action," reason tells us nothing more than that 
its existence must be logically inferred. It could tell us nothing 
more, since of it we cannot possibly have had any experience what- 
ever. Those men are strangely inconsistent who would deny it 
because they cannot imagine it, since they must confess that it must 
be unimaginable by them (even if they were in some way made 
certain of its existence) on account of their never having had any 
experience of it. 

$ 18. But to revert to the question of the Origin of Species. Let 
it be granted that Divine activity evolves new concrete forms by 
final and efficient causes (making use of living organisms as means), 
are these all the causes which operate, or is there yet another cause ? 

Species, genera, families, orders, and classes, as such are ideas ; 
they have an ideal existence in the human mind — have they no 
other ideal existence ? Every Theist must admit that the mind of 
God contains all that exists in the human mind, and infinitely more. 
It is therefore a simple truism to say that human general concep- 
tions, gathered from nature, must be ideas in the Divine mind also 
— such human conceptions being but faint and obscure adumbra- 
tions of corresponding ideas which must exist in their perfection and 
fulness in the mind of God. But there is yet a further considera- 
tion. Our ideas are ideas derived from material things, while the 
Divine ideas are ideas whence material things have been themselves 
derived. This must be so, since God is eternal, and these ideas, as 
His, must be eternal also ; whereas all the most ancient concrete 
existences in which such ideas are embodied, are relatively but 
creatures of yesterday. 



chap, xv.] THE PEDIGREE AND ORIGIN OF THE CAT. 529 

Human ideas are " true," in so far as they correspond with really 
existing things external to the human mind. But really existing, 
external things are themselves " true," in so far as they correspond 
with the eternal, archetypal or prototypal ideas of God which are 
their exemplar cause. 

The wondrously varied world of phenomena which presents itself 
on every side to the human senses, is to those senses but a confused 
mixture of sounds and colours, odours, tastes, and touches. It is 
the intellect which puts ideal order into the sensuous chaos, recog- 
nising subjectively that external order which in fact exists objec- 
tively. Amongst the orderly phenomena which cultivation enables 
the intellect to apprehend, are the variously related ideal concep- 
tions — species, genera, families, orders, and classes — which have 
their objective reality and foundation in the actually existing charac- 
ters of concrete material objects. We are able, moreover, not only 
to recognize that these ideas exist, but also to recognize that they 
form a hierarchy of conceptions. We thus come to apprehend that 
an idea embodied in some large group of creatures — some order — is 
carried to a more thorough and definite expression in some one 
family of that order, and to a still more intense degree in some 
genus of that family. It is thus that we recognize in all beasts 
the concrete embodiment of the mammalian idea, and in the car- 
nivorous type, a special, perhaps the highest, expression of that idea, 
which is carried out to its fullest manifestation in the typical Felidaa. 

We see then that the feline form is the most complete expression 
yet realized of that exemplar ideal which is less fully expressed by the 
carnivorous order considered as a whole. Thus viewed, the creatures 
to the special consideration of which this work is devoted, are seen to 
exhibit multiform relations of a very elevated character. Evolved 
through the action of antecedent organisms (of increasing specializa- 
tion of structure) as their efficient cause, they have for their final cause, 
the external realization in the material creation of one of those proto- 
typal ideas which are the several exemplar causes of the world of 
organic life, and which have eternally preceded every creative act. 
Interesting then as the animals which have here occupied us are to 
the zoologist, the physiologist, the geographer, the geologist, and 
the psychologist, they are most of all interesting to the philosopher. 
The true philosopher will never rest satisfied with a knowledge of 
material and efficient causes alone, but will ever seek to obtain 
what glimpses he may of those other causes which his reason tells 
him can never be absent from a world which is the outcome of a 
Divine Intelligence. Only at last will he rest satisfied, when, 
having traced as far as he may, the series of secondary causes, he is 
able confidently to refer to the evident though hidden action of the 
Great Author of Nature. Reason exhibits to us the whole Cosmos 
as proceeding from Him, and only when the study of his creatures 
ends by leading the student back to Him from whom they pro- 
ceeded, can that study be said to be " rational " in the highest 
sense of that word. Then only is it truly worthy of that admirable 



530 THE CAT. [chap. xv. 

human intellect which sees in the concordance between subjective 
reason and the rational laws of the objective universe, evidence that 
the human intellect itself has been created in the image and likeness 
of that intellect which is Divine. 

§ 19. Our endeavour in the pursuit of knowledge should be humbly 
but zealously to follow that natural impulse implanted in us, to 
synthesize as well as to analyse, and above all to be untiring in the 
pursuit of causes. Of the scientific man it may indeed be said : 

Felix qui potuit rerum cognoscere causas. 

No knowledge of mere facts and phenomena, however multitudin- 
ous and varied, will suffice to constitute " science." The essence 
of all science is a knowledge of causes, and only when all the 
phenomena embraced by any given study have been referred to 
their immediate causes, and when all their more remote causes have 
been duly investigated, and their several inter-relations clearly 
understood, will that study be able to take its place as a perfected 
" science." Great has been the progress of this kind which Biology 
has made during the last half century. Full of hope and promise 
is the prospect before it, long as must be its course before its per- 
fected condition can be attained. 

§ 20. To help on its progress, no course is perhaps more useful 
than that of the careful study of a succession of types belonging to 
different families of living beings. Amongst the multitude of such 
groups, that one has been here selected for examination which has 
been deemed most likely to be useful to the earnest enquirer in 
biological science who is beginning such a course of study. No 
more complete example of a perfectly organized living being can 
well be found, than that supplied by a member of what has no in- 
considerable claims to be regarded as the highest mammalian family 
— the family Felidce. 



INDEX 



* The scientific names of Cats are printed in Italics. 



aard-vark. 

Aard-vark, 468. 
Abdominal aorta, 210. 
,, cavity, 176. 

,, muscles. 141. 

ring, 141, 143. 
Abducens, 273. 
Abductor brevis pollicis, 152. 
,, indicis, 162. 

,, minimi digiti (of fore-paw), 152. 
,, minimi digiti (of hind-paw), 

162. 
,, muscles, 129. 
Aberrant forms, 490. 
Absorbent vessels, 217. 
Absorption, 167. 
Accessorius, 161. 

Accessoiy organs of respiration, 222. 
Acetabulum, 106. 
Achromatism of eye, 295. 
Acromial thoracic artery, 209. 
Acromion, 90. 
Action of bile, 188. 

,, of gastric juice, 180. 
,, of pancreatic fluid, 184. 
,, of saliva, 174. 
,, of spermatozoa, 318. 
,, of vibratile cilia, 175. 
Actions (our unconscious ones), 384. 
,, of muscles, 129. 
,, of orbital muscles, 294. 
Active powers of cat, 370. 
Activity (nervous), 305. 
Acts (mental), 386. 
Adductor of thigh, 157. 
,, muscles, 129. 
,, minimi digiti, 152. 
Adipose tissue, 17, 18. 
JElurodon, 437, 502, 513. 
jEluroidea, 475, 480. 

,, phylogeny of, 513. 

African cats, 496. 

,, gr^y> 407. 

Agreements between muscles of fore and 

hind limbs, 163. 
Ailuridse, 475. 
Air (its composition), 221. 
Air-cells, 225. 

of lungs, 223. 
Alar ligaments, 54. 
Alar thoracic artery, 210. 



anterior. 

Albumen, 12. 

Albuminoid substances, 166. 

Alimentary system, 165. 

,, canal, origin of, 341. 

,, processes summarized, 168 

Alimentation, 165. 
Ali-sphenoid, 69. 
Allantois, 325. 

,, question as to its origin, 517. 
Alligators, 462. 
Alveolar border, 73. 
Alveoli, 27. 

of lungs, 223, 225. 
Amblyctonus, 506. 
American cats, 495. 
Amnion, 322. 
Amoebae, 450, 454. 
Amoeboid movements, 194, 454. 
Amphiarthroses, 121. 
Amphicyon, 518. 
Amphilestes, 504. 
Amphioxus, 455. 
Amphistoma truncatum, 509. 
Amphitherium, 504. 
Amphiuma, 459. 
Ampullae, 300. 
Amylaceous substances, 166. 
Analogies of eye aud ear, 303. 
Anapophyses, 39. 
Anastomoses, 196. 
Anatomy, 9. 
Ancestors of cat, 512. 

,, premammalian, 518. 
Anconeal fossa, 93. 
Anconeus, 149. 
Angles of rib, 51, 52. 
Angora cat, 6. 
Animal functions, 10. 
Animals no automata, 383. 

,, what they are, 445. 
Ankle-joint, 118. 
Annelids, 450. 
Annulus (of fore-paw), 99. 
Anococcygeus, 144. 
Anomalurus, 469. 
Ant-eaters, 468. 
Antelopes, 467. 
Anterior commissure, 265. 

,, condyloid foramen, 62. 

,, crural nerve, 281, 282. 
m M 2 



532 



INDEX. 



ANTERIOR. 

Anterior hyoidean cornua, 77. 

,, nares, 59. 

,, palatine canal, 74. 

,, palatine foramen, 74. 

,, pyramids, 263, 268. 
Anthropomorphism, 527. 
Antiputrescent action of bile, 188. 
Antiquity of the cat, 3. 
Antitragus, 296. 
Anus (formation of), 343. 
Aorta, 206. 

,, abdominal, 210. 

,, thoracic, 210. 
Apes, 468, 507. 
Aphaniptera, 510. 
Apncea, 221. 
Aponeuroses, 124. 
Appendicular skeleton, 34, 89. 

,, ,, (its serial homo- 

logies), 120. 
Appendix of caecum, 183. 
Aptera, 510. 
Apteryx, 462. 
Aqueduct of Fallopius, 66. 
Aqueous humour, 294. 
Arachnida, 510. 
Arachnoid, 257. 
Arch of aorta, 207. 
Archaslurus, 436, 502, 518. 
Archetypal ideas, 529. 
Arctocyon, 506, 514, 518. 
Arctoidea, 474, 477. 
Areolar tissue, 22. 
Armadillos, 468. 

Arrangement of peritoneum, 189. 
Arterial blood, 195. 
Arteries, 196, 206. 

,, branches of carotid, 203. 
,, development of, 346. 

Artery, acromial thoracic, 209. 

,, alar thoracic, 210. 

„ axillary, 209. 

„ basilar, 209. 

,, brachial, 210. 

,, bronchial, 225. 

,, capsular, 211 

„ caudal, 213. 

,, circumflex, 210. 

,, coronary, 206. 

,, coronary of stomach, 211 

,, dorsal of foot, 214. 

,, epigastric, 213. 

,, external iliac, 213. 

,, femoral, 213. 

„ hepatic, 187, 211. 

,, hypogastric, 213. 

,, iliac, 212. 

,, innominate, 207. 

„ intercostal, 209, 210. 

,, internal iliac, 213. 

,, internal mammary, 209. 

,, interosseous, 210. 

,, long thoracic, 209 



AZYGOS. 

Artery, obturator, 213. 

„ ovarian, 211. 

,, peroneal, 213. 

„ phrenic, 209, 211. 

,, profunda, 210 

,, pudic, 213. 

,, pulmonary, 206. 

,, renal, 211. 

,, spermatic, 211. 

,, splenic, 211. 

,, subclavian, 209. 

,, superior thoracic, 209. 

,, suprarenal, 211. 

„ tibial, 213. 

,, ulnar, 210. 

,, uterine, 213. 

,, vertebral, 209. 

,, vesical, 213. 
Arthrodia, 122. 
Arthropoda, 450, 452. 
Articular processes, 35. 
Articulations of pelvic girdle, 116. 
Arytenoid cartilages, 228. 
Ascaris mystax, 509. 
Ascending colon, 182. 
,, ramus, 77. 
Ascidians, 450, 453. 
Aselli (pancreas of), 219. 
Asiatic cats, 496. 
Asphyxia, 221. 
Asses, 467. 
Assimilation, 165. 
Astragalus, 113. 
Atlas, 44. 

Attolentes auriculum, 132. 
Auditory bulla, 57. 

,, nerve, 274, 302. 
,, ossicles, 298. 
,, ,, formation of, 339. 

Auricles of heart, 205. 
Auricular surface, 46, 106. 
Aurieulo-cervicaKs, 132. 
,, submaxillary, 132. 
,, temporal nerve, 273. 
Australian region, 500. 
Automata and animals, 383. 
Automatic motions, 124. 
Automatism and consciousness, 384. 

,, ,, natural selection, 384. 

Aves, 455. 
Axial skeleton, 34. 

,, ,, development of, 332. 

Axile bodies, 22. 
Axillary artery, 209. 
, glands, 218. 
,, nerve, 279. 
,, veins, 215. 
Axis, ossification of, 334. 

,, cylinder, 254. 

,, vertebra, 43. 

,, and atlas, ligaments of, 54. 
Axolotl, 459, 523. 
Azygos veins, 217. 



C: 



INDEX. 



533 



BACK-BONE. 

Back-bone (ossification of), 334. 
Badger (the), 475. 
Balance of nutrition and waste, 166. 
Balanoglossus, 450. 
Ball-and-socket joints, 122. 
Bandicoots, 468. 
Base of skull, 79. 
Basi-cranial axis, 84. 

,, plate, 337. 

Basi-facial axis, 85. 
Basi-hyal, 78. 

,, occipital, 61. 

,, sphenoid, 69. 
Basilar artery, 209. 

,, membrane, 301. 
Bassaris, 474. 
Batrachia, 456, 459. 
Bats, 468, 507. 
Bay cat, 401. 
Bearing of psychology on development, 

386. 
Bears, 468, 474, 476. 
Beasts, 466. 
Beavers, 469. 

Bell (respiratory nerve of), 278, 279. 
Beni Hassan, 3. 
Beroe, 456. 

Bertholin's glands, 246. 
Biceps, 148. 

,, fern oris, 158. 
Bicipital groove, 91. 

, muscles, 128. 
Bicuspid valve, 204. 
Bilateral symmetry, 15. 
Bile, 188. 
Bile ducts, 186. 
Bilifulvin, 188. 
Biliverdin, 188. 
Biologv, 8. 
Birds, *455, 462. 

,, feet feathered, 377. 
Bisons, 467. 
Bladder, 235. 

„ gall. 186. 
Blastodermic vesicle, 319. 
Blind spot, 292, 293. 
^lood, 193. 

,, development of, 331. 
,, its change of colour, 203. 
,, its gaseous changes, 221. 
„ of the kidney, 234. 
Blood-vessels (great), 201. 

,, formation of, 345. 

Body-cavity, what it is, 26. 
Body and soul (reciprocal action); 383. 
Body (its mechanical support), 129. 

,, of the cat, 14. 

,, of hyoid, 78. 

,, of rib, 51. 

,, of sternum, 50. 

,, of vertebra, 35. 
Bone, 19. 

,, corpuscles, 19. 



Bone, development of, 331. 

,, its growth, 20. 
Bony labyrinth, 299. 
Bornean cat, 419. 
Bothriocephalus decipiens, 509. 

felis, 509. 
Boundaries of abdomen, 176. 
Brachial artery, 210. 
,, plexus, 278. 
,, vein, 215. 
Brachialis anticus, 148. 
Brain, 259. 

,, development of, 357. 
Branchiata, 456. 
Breastbone, 49. 
Breasts, 239. 
Breathing air, 226. 
Breeding of cat, 8. 
Breeds of domestic cat, 5. 
Broad ligaments, 247. 

,, ,, of liver, 185. 

Bronchi, 223. 
Bronchial tubes, 225. 
Bruner's glands, 181. 
Bryozoa, 450. 
Bubastis, 3. 
Buccal glands, 174. 
Buccinator, 133. 
Buffaloes, 467. 

Burt Wilder (Professor), 377. 
Bushy-tailed red-spotted cat, 416. 

Cjdcum, 182. 

Cainozoic strata, 501, 502. 

Calcaneum, 113. 

Calloso-marginal sulcus, 269. 

Camels, 467. 

Canal (vertebral), 35. 

,, ali-sphenoid, 439, 477. 
,, of Petit, 294. 
Canaliculi, 19. 
Canalis centralis, 259. 
,, membranacea, 301. 
,, reuniens, 301. 
Canals (portal), 187. 

,, semi-circular, 300. 
Cancelli, 20. 
Canidse, 474, 479, 518. 
Canine teeth, 28. 
,, fossa, 73. 
Canthus of eye, 288. 
Capillaries, 197. 
Capitellum, 93. 
Capitular surfaces, 37, 38. 
Capitulum of rib, 50. 
Capsular artery, 211. 
,, veins, 216. 
,, ligament of knee, 118. 
,, ,, of shoulder, 100. 

,, ,, of spine, 53. 

of thigh, 116. 
Capsule of lens, 294. 
Capsules (supra-renal), 237. 



534 



INDEX. 



CAPSULES. 

Capsules, synovial, 122. 
,, of cartilage, 18. 
Caracal, 426. 

Carbonic acid (exchange of), 220. 
Cardia, 178. 
Cardiac plexus, 284. 
Cardinal veins, 347. 
Carnivora, 469, 471. 

,, characters of, 473. 
,, component groups of, 474. 
Carotid arteries, 208. 
„ canal, 83. 
,, foramen, 476. 
Carpus, 96\ 
Carthusian cat, 6. 
Cartilage, 18. 

,, development of, 330. 
Cartilages (costal), 50, 52. 
,, of larynx, 227. 
,, of nose, 286. 
Cartilaginous cranium (formation of), 337. 
, , skeleton (backbone), 333. 

Cat, Angora, 6. 
,, Carthusian, 6. 
,, gestation of, 8. 
,, its place in nature, 440, 493. 
,, Malay, 7. 
,, Manx, 7. 
,, origin of the word, 2. 
,, Persian, 6. 

,, regions of the world, 497 
,, Siamese, 6. 
,, teeth of, 27. 
,, tortoiseshell, 6. 
,, whiskers of, 24. 
Categories of vertebras, 36. 
Catless regions, 496. 
Cat-mind, 386. 
Catolynx, 404. 

Cat's ancestors, viverrine, 512. 
,, antiquity, 3. 
,, body, 14 ; its chemical constitution, 

12 ; diagram of, 16. 
,, emotions, 368. 
,, eyes, 5. 
,, feet, pads of, '25. 
,, genus (its position), 489 
,, languagp, 371. 
,, origin. 519. 
,, pedigree, 517, 518. 
,, place in nature, 440. 
,, psychical powers, 366. 
,, quasi-intelligence, 367. 
Cats born with stump-tails, 7. 
,, colours of, 5. 
,, extinct kinds, 432. 
„ in Egypt, 3. 
,, in the Middle Ages, 2. 
,, influences of environment on, 8. 
,, number of kinds, 431. 
,, of Isle of Man, 7. 
,, of Mombas, 7. 
,, of Paraguay, 7. 



CHEETAH. 

Cats, their food, 8. 
Cattle, 467. 
Cauda equina, 259. 
Caudal artery, 213. 
,, vein, 216. 
,, vertebrae, 46. 
„ „ of Malay cat, 46, 47. 

,, ,, of Manx cat, 46. 

Caudo-cavernosus, 144. 
Causal action of sensations, 383. 
Cause of psych ogenesis, 526. 
Causes, 526, 529. 

,, a knowledge of, alone constitutes 
science, 530. 
Cavities of heart, 201. 
of skull, 85. 
Cavity of abdomen, 176. 
Cells, 17 (note). 
„ of liver, 188. 
,, nerve, 255. 
Cement, 31. 

,, formation of, 344. 
Centetes, 468. 
Centipedes, 450. 

Centripetal and centrifugal fibres, 308. 
Centrum, 35. 
Cephalo-humeral, 147. 
Cerato-hyal, 78. 
Cerebellar fossa of skull, 83. 
Cerebellum, 259, 262. 

,, its functions, 311. 

Cerebral hemispheres, 260. 
Cerebrum, 259. 

,, its functions, 312. 

Cervical glands, 218. 
„ nerves, 277. 
,, plexus, 277. 
,, vertebra?, 40. 
,, ,, ossification of, 334. 

Cervicalis ascendens, 138. 
Cervix of tooth, 27. 
Cestum Veneris, 450. 
Cetacea, 467, 471. 
Change of colour of blood, 203. 
Changes after death, 522. 
Characters of cat (the most general), 440. 
,, of cat's-order, 473. 

,, of cat's sub-order, 489. 

,, of cat as a vertebrate, 454. 

Characters distinguishing cat from crea- 
tures devoid of life, 441, 445 ; from 
plants, 448 ; from Didelphia, 471. 
Characters distinguishing cat's class from 
fishes, 458 ; from Batrachians, 460 ; 
from Branch iata, 461 ; from reptiles, 
462 ; from birds, 465 ; from Mono- 
condyla, 466 ; from Ornithodelphia, 
470 ; from Hyamidae, 488 ; from Vi- 
verridse, 488 : from Cryptoproctidse, 489. 
Chati, 409. 
Cham, 420. 
Cheek ligaments, 54. 
Cheetah, 427. 



INDEX. 



535 



CHEIROPTERA. 

Cheiroptera, 468, 472. 

Chemical constitution of cat's body, 12. 

Chevron bones, 47. 

Chevrotains, 467. 

Chiasma (of the nerves), 270. 

Chinese cat, 41 4. 

Choanoid muscle, 132. 

Chorda tympaui, 274. 

Chorio capillaris, 291. 

Chorion, 323. 

Choroid, 290. 

,, plexus, 266. 
Chyle, 181. 
Chyme, 180. 

Cilia (vibratile), 25, 175. 
Ciliary artery, 208. 
,, muscle, 292. 
,, processes, 290. 
Ciliated epithelium, 25, 175. 
Cingulum, 28. 
Circle of Willis, 209. 
Circulation (organs of), 192. 

,, its course, 203 

,, in kidney, 234. 

,, in liver, 187. 

Circumduction, 128. 
Circumflex artery, 210. 

„ nerves, 278, 279. 

Circumflexus palati, 135. 
Circumvallate papillae, 172. 
Civet cats, 469, 475, 481. 
Classes of vertebrata, 455. 
Classification of muscles, 130. 
,, zoological, 449. 

Clavicle, 90. 

Claws, how retracted and protruded, 102. 
Cleido-mastoid, 134. 
Clinoid processes, 69, 71. 
Clitoris, 246. 
Cloaca, 343. 
Clouded tiger, 398. 
Coagulation, 193. 
Coati-mundis, 474. 
Cochlea, 299. 
Cochlear part of labyrinth, 301. 

,, nerve, 302. 
Cod (structure of), 456. 
Ccelentera, 450, 453. 
Coenurus, 509. 
Colloids, 167. 
Colocollo, 413. 
Colon, 182. 
Colours of cats, 5. 
Columns carneae, 204. 
Columnar epithelium, 2fi. 
Combustion of tissues, 222. 
Commissures of spinal cord, 259. 
Common jungle cat, 420. 
Comparative anatomy, 10. 
Complemental air, 226. 
Complete joints, 121. 
Complexus, 135. 
Composition of air, 221. 



CORPUSCLES. 

Composition of cat's body and its systems 
of parts and organs, 374. 
,, of organs, 375. 

,, of tissues, 375. 

Compressor naris, 131. 

,, urethra?,, 144. 

Concha, 295. 

Conditions of nervous activity, 307. 
Condyle (of mandible), 60, 77. 
Condyles of femur, 108. 

of tibia, 110. 
Cones and rods, 292, 293. 
Coni vasculosi, 244. 
Conical papilla?, 172. 
Conjunctiva, 288, 289. 
Connective tissue, 16, 17. 

,, ,, development of, 330. 

Consciousness and automatism, 384. 
Consentience, 378. 
Constrictors of pharynx, 185. 
Continuity (law of), 443. 
Contractility, 127. 
Contraction (muscular), 124, 126. 
Conus arteriosus, 205. 
Convolutions, 261, 268. 
Coordinating system, 253. 
Coordination of psychical powers, 374. 
Coraco-brachialis, 148. 

,, clavicular ligament, 100. 
Coracoid process, 90. 
Coral animals, 450. 
Cordas tendinea?, 204. 
Cord, spermatic, 243, 245. 
Cords (vocal), 227, 229. 

,, of sympathetic, 283 
Corium, 22. 
Cornea, 290. 

Cornua of lateral ventricles, 267. 
Coronal suture, 60. 
Coronary arteries, 206. 

,, artery of stomach, 211. 

,, vein, 205. 
Coronoid fossa, 93. 

,, process of mandible, 77 ; of 
ulna, 96. 
Corpora Aurantii, 204. 

,, cavernosa, 242. 

,, mammillaria, 263. 

,, striata, 268 ; their functions, 311. 

,, quadrigemina, 262. 

,, ,, their function, 311. 

Corpus albicans, 263. 

,, callosum, 261. 

,, ,, development of, 359. 

,, geniculatum, 262. 

,, Highmorianum, 243. 

,, luteum, 251. 

,, spongiosum, 242. 

,, . trapezoideum, 263. 
Corpuscles of connective tissue, 16. 
,, of bone, 19. 
,, of blood, 194. 
,, lymph, 195. 



536 



INDEX. 



CORPUSCLES. 

Corpuscles, Malpighian, 233. 

,, nerve, 255. 

Correspondences between skeleton of fore 

and hind limbs, 119. 
Corti (organ of), 302. 
Cosmos (the), 529. 
Costse, 50. 
Costal cartilages, 50, 52. 

,, ligaments, 55. 

,, surfaces, 37. 
Cotyloid cavity, 106. 

,, ligament, 116. 
Coughing, 226. 

Course of blood through heart, 203, 204. 
Cowper's glands, 243. 
Crabs, 450. 
Cranial bones (formation of), 338. 

,, nerves, 269 ; their functions, 
309 ; development of, 361. 
Cranium, 57. 
Creation, 527, 528. 
Creodonta, 504. 

,, their affinities, 515. 

Cribriform plate, 71. 

,, plane of, 85. 
Cricoid cartilage, 227. 
Crocodiles, 462. 
Crossarchus, 481. 
Crucial ligaments, 117 

„ sulcus, 269. 
Crura of olfactory lobes, 264, 270. 

,, of stapes, 298. 

,, cerebri, *60, 263. 
Crureus, 159. 
Cryptoprocta, 518. 
Cryptoproctidae, 475, 483, 488. 
Crystalline lens, 293. 
Crystalloids, 167. 
Cuboid bone, 115. 
Cumulus, 250. 
Cuneiform bones, 96, 115. 
Cuttlefishes, 450, 452. 
Cycles of change, 442. 
Cynictis, 481. 
Cynodictis, 507, 514, 518. 
Cynodon, 506, 514, 518. 
Cyncelurus, 513, 518. 
,, jubata, 427. 

,, lanea, 429. 

Cynogale, 481. 
Cynoidea, 474, 479. 
Cystic duct, 186. 

,, fissure, 186. 
Cy.sticereus cellulosa, 509. 



Dautos, 243. 
Dasyures, 468. 
Dasyurus, 518. 
David, Pere, 6. 
Dead bodies, 385. 

Death (changes of decomposition), 522. 
,, stiff ening, 128. 



DEVELOPMENT. 

Decidua, 327. 
Deciduous dentition, 29. 
Deer, 467. 

Definition of an organism, 9. 
Deltoid, 147. 
Delusive feelings, 308. 
Dental formula, 30. 
,, nerves, 273. 
Dentine, 31. 

,, formation of, 344. 
Dentition (milk), 29. 
Depressor muscles, 129. 
Derivative creation, 527. 
Dermis, 21, 22. 
Descending aorta, 208. 

,, colour, 182. 

Development, 11, 317. 

,, and psychology, 386. 

,, of alimentary canal, 341. 

,, of anus, 343. 

,, of arteries, 346. 

, , of auditory ossicles, 339. 

,, of axial skeleton, 332. 

of blood, 331. 

,, of blood-vessels, 345. 

,, of bone, 331. 

,, of brain, 357. 

,, of cartilage, 330. 

,, of cartilages of vertebral 

column, 333. 

,, of cartilaginous cranium, 

337. 

,, of cement, 344. 

,, of connective tissue, 330. 

,, of cranial bones, 338. 

,, of cranial nerves, 361. 

,, of dentine, 344. 

,, of ear, 362. 

,, of elastic tissue, 330. 

,, of enamel, 344. 

,, of epithelial tissue, 331 

of eye, 361. 

,, of Graafian follicles, 355. 

,, of heart, 345 

,, of jaws, 336. 

,, of kidneys, 351. 

,, of larynx, 350. 

„ of linibs, 339. 

,, of liver, 344. 

,, of lungs, 349. 

,, of lymphatic system, 349. 

,, of mouth, 342. 

,, of muscles, 341. 

,, of muscular tissue, 331. 

,, of nares, 337. 

,, of nervous system, 355. 

,, of nervous tissue, 331. 

,, of nose, 363. 

,, of organs, 329. 

,, of ova, 354. 

,, of ovary, 352. 

,, of pancreas, 344. 

„ of penis, 352. 



INDEX. 



537 



DEVELOPMENT. 

Development of peritoneal cavity, 322. 
,, of peritoneum, 345. 

„ of salivary glands, 344. 

of skull, 335. 
,, of species, 512. 

,, of spermatozoa, 245. 

,, of spinal marrow, 356. 

,, .of spleen, 350. 
,, of suprarenal corpuscles, 

351. 
,, of testes, 352. 

,, of the teeth, 343. 

,, of thymus gland, 350. 

,, of thyroid body, 350. 

,, of tissues, 329. 

,, of urinary organs, 350. 

,, of vagina and uterus, 352. 

,, of veins, 346. 

,, of visceral clefts, 335. 

Developmental changes before impregna- 
tion, 317. 
,, their principle, 387. 

Diagram of cat's body, 16. 
Dialysis, 167. 
Diaphragm, 141. 
Diarthroses, 121. 
Diastema, 28. 
Dicyema, 450 
Didelphia, 469. 
Didelphys, 504, 518. 
Didymictis, 506. 

Difference between skeleton of fore and 
hind limbs, 119. 
,, between muscles of fore and 
hind limbs, 163. 
Differentiation. 329. 
Different kinds of cats, 390. 

,, possible modes of evolution, 
519. 
Diffusion of air in lungs, 229. 
Digastric muscles, 128, 133. 
Digestion, 167. 
Digitigrade progression, 129. 
Digits, maximum of muscles to, in fore- 
paw, 153. 
,, maximum number of muscles to, 
in hind-paw, 163. 
Dinictis, 435, 502, 518. 
Dinotheria, 467. 
Diploe, 86. 

Direction of muscles, 153. 
Discus proligerus, 250. 
Diseases of cat, 511. 
Distinction between crystalloids and 

colloids, 167. 
Distoma lanceolatum, 509. 
Division of nervous system, 253. 
Dogs, 468, 474. 
Dolphins, 467. 
Domestic cat, breeds of, 5. 
Dorsal aorta, 208. 

,, artery of foot, 214. 
,, common ligament, 53. 



ENAMEL. 

Dorsal nerves, 277, 281. 

,, plates, 321. 

,, spinal nerves, 277. 

,, vertebra, 36, 37. 

,, vertebra? (tenth and eleventh), 
Dorso-epitrochlear (external), 137. 

,, epitrochlear (inner), 137. 
Double hinge-joints, 123. 
Dromatherium, 504. 
Duct (Gaertner's), 250. 

,, thoracic, 218. 
Ductless glands, 237. 
Ducts of liver, 186. 

,, lymphatic, 218. 

,, pancreatic, 183. 

,, Stenson's, 172. 

,, Wharton's, 173. 
Ductus arteriosus, 206, 346. 

,, communis choledochus, 186. 

,, Cuvieri, 347. 

,, omphalo-entericus, 327. 

,, venosus (fissure of), 185. 
Dugong, 467. 
Duodenum, 181. 
Dura mater, 256, 261. 



Eae, development of, 362. 

,, external, 295. 

,, its middle part, 297. 

,, muscles, 131. 
Ear and eye, analogies of, 303. 
Earthworms, 450. 
Echidna, 469. 
Echinoderma, 450. 
Ecteron, 21. 
Ecto-cuneiform, 115. 
Ectoderm, 453 
Ectodermic cells, 319. 
Edentata, 468, 471. 
Effects of bile on food, 188. 
Efficient causes, 527, 529. 
Egyptian cat, 5, 419. 
Egyptians and the cat, 3. 
Eighth caudal vertebra, 47. 

,, nerve, 274. 
Elastic ligaments, 123. 

,, ,, of claw, 102. 

„ tissue, 17. 

,, ,, development of, 330. 

Elasticity of lungs, 224. 
Electricity and nervous activity, 306. 
Elementary substances of body, 166. 
Elements (of nervous tissue), 254. 
Elevator muscles, 129. 
Eleventh dorsal vertebra, 32. 

,, nerve, 275. 
Embryo (its first appearance), 320. 
Embryonal area, 320. 
Emotions of cat, 368. 
Enamel, 31, 32. 

„ formation of, 344. 
„ organ, 32, 343. 



538 



INDEX. 



ENARTHRODIA. 

Enarthrodia, 122. 
Encephalon, 259. 
Encystment of parasites, 509. 
End organs, 255. 
Enderon, 21. 
Endoderm, 453. 
Endodermic cells, 319. 
Endolvmph, 301. 
Endoplast, 330. 
Endo-skeletal muscles, 130. 

,, skeleton, 21. 
Endosmosis, 167. 
Ensiform process, 50. 
Enteropneusta, 450. 
Ento-cuneiform, 115. 

,, tympanic, 65. 
Environment, 494. 
Eocene strata, 502. 
Ependyma, 260. 
Epiblastic cells, 319. 
Epidermis, 21. 
Epididymis, 243, 244. 
Epigastric artery, 213. 
,, plexus, 284. 

Epiglottis, 228. 
Epi-hyal, 78. 
Epiotic, 69. 
Epiphyses, 20, 21. 

,, vertebral, 334. 
Epithelial tissue, 21. 

,, „ development of, 331. 

Epithelium, 21, 26. 

,, ciliated, 175. 

Equivalence of male and female parts in 

impregnation, 318. 
Erectile tissue, 242. 
Erector spinee, 138. 
Essential respiratory organs, 223. 
Eternity of archetypal ideals, 528. 
Ethiopian region, 498. 
Ethmoid, 71. 
Ethmoidal artery, 208. 
Ethmo-turbinal, 71. 

,, vomerine plate, 337. 
Eusmilus, 437, 491, 503, 518. 
Eustachian tube, 66, 298. 
Evolution, 11, 512, 521. 

,, its possible modes, 519. 

,, of Machserodus, 522. 
Examples of orders of levers, 130. 
Exchange (gaseous), 220. 
Excito-motor action, 310. 
Excretin, 188. 
Exemplar causes, 529. 
Existing cats, 430. 
Ex-occipital, 61. 
Exo-skeletal muscles, 130. 
Exo-skeleton, 21. 
Exosmosis, 167. 
Experience as to origin of new forms, 521. 

,, and origin of life, 524. 

,, as to modes of origin, 524. 

Extensor brevis digitorum, 160. 



FELIS. 

Extensor carpi ulnaris, 152. 

,, communis digitorum, 151. 

,, indicis, 152. 

,, longus digitorum pedis, 159. 

,, metacarpi pollicis, 152. 

,, minimi digiti, 151. 

,, muscles, 128. 

,, secundi internodii pollicis, 152. 
Extensores carpi radial is, 151. 
External annular ligament (of hind-paw), 
162. 

,, auditory meatus, 296. 

,, cutaneous nerve, 281, 282. 

,, dorso-epitrochlear, 137. 

,, ear, 295. 

,, iliac artery, 213. 

,, malleolus, 112. 

,, oblique, 141. 

,, and internal respiration, 221 ; 
sensations, 313. 

,, influences on cats, 8. 
Extinct cats, 432. 
Eye, 288. 
,, recti muscle of, 132. 
,, as an optical instrument, 294. 
,, development of, 361. 
,, and ear (analogies of), 303. 
Eyeball, 289. 
Eyelids, 288. 

„ functions of, 294. 
Eyes of cats, 5. 
Eyra, 412. 

Facial arterv, 208. 
„ gland, 173. 
,, nerve, 274. 
Facts anatomical and pathological, 377. 
Falciform ligament of liver, 185, 191. 
Fallopian tubes, 247. 
False ribs, 50. 

,, vertebra?, 36. 

,, vocal cords, 229. 
Falx cerebri, 256, 261. 
Fascia, palmar, 149. 

,, spermatic, 243. 

,, superficial, 143. 

,, transversal is, 143. 
Fasciae, 124. 
Fat, 18. 
Fauces, 170. 

Feathered bird's feet, 377. 
Feelings, 304. 
Felidas, 475, 487. 
Felis, 518. 
Felis aurata, 401. 

,, badia, 419. 

,, bengalensis, 403. 

,, borealis, 424. 

,, brachyurus, 399. 

,, caligata, 419. 

,, canadensis, 425. 

,, caracal, 426. 

,, catus, 4, 420. 



INDEX. 



539 



FELIS. 

Felis caudal us, 421. 
celidogaster, 406. 
Chaus, 420. 
chinensis, 414. 
christoli, 432. 
colocollo, 413. 
concolor, 397. 
Duvancelli, 404. 
crythrotis, 420. 
cuptilura, 416. 
^2/ra, 412. 
Fonteirii, 394. 
grisea, 408. 
guigna, 410. 
guttula, 410. 
Herschelii, 415. 
isabellina, 426. 
javanensis, 416. 
Jerdoni, 415. 
jubata, 427. 
lanca, 429. 
Zeo, 392. 
lupulinus, 426. 
lijncus, 424. 
macrocelis, 398. 
macroura, 409. 
maculata, 425. 
?)ianiculata, 5. 
Manul, 422. 
marmorata, 404. 
megalotis, 417. 
melanura, 408. 
microtis, 417. 
minuta, 415. 
mtfe, 409. 
neglecta, 407. 
onca, 397. 
ornata, 420. 
pajeros, 423. 
pardalis, 408. 
pardina, 426. 
par din o ides, 411. 
pardochroa, 403. 
pardoides, 408. 
pardus, 394. 
joicte, 408. 
planiceps, 417. 
rubiginosa, 413. 
rii/a, 425. 
rutila, 406. 
scripta, 400. 
sencgalensis, 406, 407. 
serval, 406. 
servalina, 408. 
Shawiana, 421. 
spefcra, 432, 502. 
tigrina, 409. 
%ra, 393. 
torquata, 420. 
*rfe&s, 400. 
Tulliana, 396. 
uncia, 395. 
viverrina, 401. 



info's yaguarondi, 412. 
Felting, 23. 

Female generative organs, 245. 
Femoral artery, 213. 

,, vein, 216. 
Femur, 107. 
Fenestra ovalis, 68, 297. 

,, rotunda, 68, 298. 
Fenestration, 329. 
Fibres (nerve), 254. 
Fibrillar (muscular), 126. 
Fibrin, 193. 

,, muscle, 125. 
Fibre-cartilage, 18. 
Fibula, 112. 
Fifth caudal vertebra, 47. 

,, cervical veitebra, 40. 

,,' dorsal vertebra, 37. 

,, lumbar vertebra, 39, 40. 

,, pair of nerves, 271. 

,, ventricle, 266, 267. 

,, ,, (nature and origin of), 359. 

Filaments (spermatic), 245. 
Filum terminale, 257. 
Fimbriae, 247. 
Final causes, 527. 

First appearance of embryo, 320 ; of 
notochord, 321. 

,, pair of nerves, 270. 

„ rib, 51. 

,, segmentation nucleus, 318. 

,, visceral arch, 337. 
Fishing cat, 401. 
Fissura Glaseri, 65. 
Fissure (portal), 185. 

,, of ductus venosus, 185. 
,, umbilical, 185. 
,, great longitudinal, 261. 
,, of cerebrum, 261. 
Fissures of liver, 185. 

,, of spinal cord, 258. 
Flagellate animals, 450. 
Flat-headed cat, 417. 
Flattened papillre, 172. 
Flea of the cat, 510. 
Flexor brevis digit orum, 161. 

,, bivvis minimi digiti, 152. 

,, carpi radialis, 149. 

,, carpi ulnaris, 151. 

,, longus digitorum, 161. 

,, longus hallucis, 161. 

, perforans of fore-paw, 150 

,, perforans of hind-paw, 161. 

,, perforatus of fore paw, 150. 

,, perforatus of hind paw, 101. 

„ profundus digitorum. 150. 

,, sublimis digitorum, 150. 

,, muscles, 128. 
Floating rib, 51. 

Fluids passing through membranes, 167. 
Flukes, 450, 509. 
Foetus, 328. 
Folds of mucous membrane, 27. 



540 



INDEX. 



FOLLICLES. 

Follicles (Graafian), 249. 
Fontanel's spotted cat, 400. 
Food, 165. 

,, of cats, 8. 
Foramen anterior condyloid, 62. 
,, anterior palatine, 74. 
,, carotid, 476. 
,, incisor, 74. 
,, inferior dental, 77. 
,, infra-orbital, 73. 
,, lacerum jugulare, 62. 
,, lacerum posterius, 62. 
,, magnum, 61. 
,, magnum (plane of), 85. 
,, mental, 77. 
,, obturator, 104, 107. 
,, optic, 71. 
,, ovale, 70. 
,, ovale (of heart), 346. 
,, post-glenoid, 67. 
,, posterior palatine, 76. 
,, rotundum, 70. 
,, spheno-palatine, 76. 
,, stylo-mastoid, 65. 
,, supra-condyloid, 91. 
Foramen of Monro, 266, 267. 

,, of Winslow, 190. 
Foramina (inter-vertebral), 36. 

,, sacral, 45. 
Force, internal, 525. 

,, intra-organic, 380. 
Fore-arm (muscles of), 149. 
Fore-limb (muscles of), 145. 

,', nerves of, 278. 
Fore-paw (muscles of), 152. 
Fore and bind limbs (differences and 
correspondences between their skele- 
tons), 119. 
Form of peritoneum, 189. 
Formse transeuntes, 389. 
Formula (dental), 30. 
Fornix, 265. 

„ development of, 359. 
Fossa, anconeal, 93. 
,, coronoid, 93. 
,, iliac, 106. 
,, inter-condyloid, 109 
„ mesopterygoid, 70. 
,, olecranal, 93. 
,, ovalis, 205. 
,, pterygoid, 70. 
,, trochanteric, 107. 
Fossae of nose, 286. 
Fossil cats, 432, 489, 502. 
Fossils, 501. 

Fourth caudal vertebra, 47. 
,, pair of nerves, 271. 
,, ventricle, 265. 
Foussa (the), 483. 
Framum lingua?, 172. 
Frog (structure of), 459. 
Frontal bone, 63. 
lobe, 264. 



GENERAL. 

Frontal sinuses, 64, 86. 
Fronto-auricular, 131. 
Fulcra, 129. 
Functions, 10. 

,, of corpora striata, 311. 

,, of corpora quadrigemina, 311. 

,, of cranial nerves, 309. 

,, of eyelids, 294. 
of kidney, 234. 

,, of large intestine, 183. 

„ of liver, 188. 

,, of medulla oblongata, 310. 

,, of muscular tissue, 126. 

,, of muscles, 129. 

,, of nervous system, 304. 

,, of optic thalami, 311. 

,, of ovary, 250. 

,, of pancreas, 184. 

,, of parts of internal ear, 303. 

,, of respiration, 220. 

,, of saliva, 174. 

,, of small intestine, 181. 

,, of spinal nerves, 307. 

,, of spleen, 238. 

,, of stomach, 179. 

,, of sympathetic system, 312. 

,, of the cerebellum, 311. 

,, of the cerebrum, 312. 

„ of the spinal cord, 309. 

„ of the teeth, 171. 
Fundamental similarities of male and 

female sexual organs, 354. 
Fungiform papilla?, 172. 
Furculum, 462. 

Gaertner's duct, 250. 
Galecynus, 507, 514, 518. 
Gall-bladder, 186. 
Ganglia (semi-lunar), 284. 
Gangliated sympathetic cords, 283. 
Ganglion (Gasserian), 272. 
„ impar, 284. 
„ Meckel's, 273. 
„ spheno- palatine, 273. 
Gaseous exchange, 220. 
Gases (poisonous), 221. 
Gasserian ganglia, 272. 
Gastric juice, 179. 

,, nerves. 275. 
Gastrocnemius, 160. 
Gastro-colic omentum, 190. 
Gastrodisc, 320. 
Gastro-hepatic omentum, 190. 
Gastro-splenic omentum, 190. 
Gelatine, 12. 

Gelatinoid substances, 166. 
Gemelli, 156. 

Genealogy of cat, 517, 518. 
General coloration of Felidae, 430. 

,, geographical regions, 497. 

,, view of pectoral limb's skeleton, 
102 ; of pelvic limb's skeleton, 
119 ; of peritoneum, 191. 



INDEX. 



541 



GENERALIZED. 

Generalized forms, 490. 

,, view of skull, 87. 
Generation of heat, 222. 
Generative organs, 240. 

„ ,, male, 241. 

,, ,, female, 245. 

Generic names, 392. 
Genets, 481. 
Genio-hyoglossus, 134. 
Genio-hyoid, 134. 
Genito-crural nerve, 281, 282. 
Genu (of corpus caliosum), 265. ' 
Geoff roy's cat, 410. 
Geographical distribution of wild cat, 3. 

,, relations of cats, 495. 

Geography, organic, 11. 
Geological facts, 501. 
Gephyrea, 450. 
Germ area, 320. 
Germ-cell and sperm -cell, 318. 
Germinal vesicle and spot, 250. 
Gestation, 247, 328. 
,, of cats, 8. 
Gills, 456. 

Ginglyform joints, 122. 
Giraffes, 467, 507. 
Giraldes (organ of), 244. 
Glands (Harderian), 289. 

,, axillary, 21 1. 

,, of Bertholin, 246. 

,, Bruner's, 181. 

,, buccal, 174. 

,, cervical, 218. 

,, Cowper's, 243. 

,, ductless, 237. 

,, facial, 173. 

,, of small intestine, 181. 

,, labial, 170. 

„ lachrymal, 289. 

,, of Lieberkuhn, 181. 

,, lymphatic, 198, 218. 

,,. Meibomian, 288. 

,, mesenteric, 218. 

,, parotid, 172. 

,, peptic, 179. 

,, pineal, 266. 

,, prostate, "J 42. 

,, salivary, 172. 

,, submaxillary, 173. 

„ (their nature) 230. 

„ of thigh, 218. 

,, thyroid, 237. 

,, tracheal, 218. 

,, zygomatic, 173. 
Glenoid ligament, 100. 

,, surface, 58. 
Globus major and minor, 243. 
Glomerulus, 234. 
Glosso-pharyngeal nerve, 274. 
Glottis, 226. 

Gluteal nerves, 281, 282. 
Gluteus maximus, 154. 

., medius, 155. 



HIERARCHY. 

Gluteus minimus, 156. 
,, quartus, 156. 
Glutton (the), 475. 
Glycogen, 188. 
Goats, 467. 

God implied in nature, 527. 
Golden -haired cat, 406. 
Gomphosis, 121. 
Graafian follicles, 249. 

,, development of, 355. 
Gracilis, 158. 
Granular layers, 293. 
Great blood-vessels, 201. 
,, longitudinal fissure, 261. 
,, omentum, 176, 190. 
,, sciatic nerve, 282. 
Gregarinida, 450. 
Grey African cat, 407. 
Grey nerve fibres, 255. 

,, nervous matter, 256. 
Groups composing Carnivora, 474. 

,, (zoological), what they really 
are, 520 
Growths of bone, 20. 
Gullet, 175. 
Gulo, 475. 

Gustatory bulbs, 285. 
,, cells, 285. 
,, nerve, 273. 
,, pores, 286. 
Gymnura, 468, 518. 
Gyri, 261, 268. 

Hair, 22. 
Hallux, 115. 
Hamular process, 70. 
Harderian gland, 289. 
Hares, 469. 
Haversian canals, 19. 
Head (muscles of), 131. 

,, skeleton of, 56. 

,, and tail folds of embryo, 322. 

,, and trunk (skeleton of), 34. 
Hearing, 315 

,, organ of, 295. 
Heart, 199. 

,, formation of, 345. 
Heat, 494. 

,, generation, 222. 
Hedgehog, 468. 
Heiicotrema, 301. 
Hemispheres of brain, 260. 
Hemistoma cordatum, 509. 
Hepatic arterv, 187, 211. 
,, cells, 188. 
,, ducts, 186. 
,, veins, 187. 
Herpestes, 481, 482. 
Hexicology, 11. 

of cat, 494. 
Hiatus Fallopii, 66. 
Hierarchy of functions, 375. 
,, of parts, 374. 



542 



INDEX. 



HIND. 

Hind foot (articulations and ligaments 
of), 118. 

„ leg (ligaments and articulations 
of), 116. 
Hind limb (muscles of), 154. 
Hinge joints, 1 22. 
Hip (muscles of), 154. 
Hippocampal gyrus, 268. 
Hippocampus major, 267. 
Hippopotamus, 467. 
Histology, 9. 

Hoplophorieus, 433, 502, 518. 
Horizontal ramus, 77. 
H orns of spinal cord, 259. 
Horses, 467. 

Human mental powers, 372. 
Humerus, 90. 
Humour (aqueous), 294. 

,, vitreous, 293. 
Hunting leopard, 427. 
Hysenarctos, 507, 514, 518. 
Hyeenictis, 514. 
Hyamidaj, 475, 483, 488, 518. 
Hyamodon, 506, 514, 518. 
Hyaline cartilage, 18. 
Hydatid of Morgagni, 244. 
Hydra, 450. 
Hymen, 246. 
Hyoglossns, 134. 
Hyoid, 57, 77. 
Hyoidean cornua, 77. 
Hypapophysial parts, 39, 44. 
Hyperapophyses, 43. 
Hypoblastic cells, 319. 
Hypogastric artery, 213. 
,, plexus, 284. 

Hypoglossal nerve, 275. 
Hypozoa, 450, 454. 
Hypsiprymnus, 504. 
Hyrax, 467. 

Ichneumons, 481. 

Ictitherium, 507, 513, 518. 

Idealism, 385. 

Ideas (prototypal or archetypal), 528. 

Ileum 180. 

Ileo-csecal valve, 183. 

Iliac artery, 212. 

,, fossa, 106. 

,, vein, 216. 
Iliacus, 156. 
Ilium, 105. 
Ilio-coccygeus, 143. 
Ilio-hypogastric nerve, 281, 282. 
Ilio-inguinal nerve, 281, 282. 
Immaterial realities, 385. 

,, and material substances, 378. 

Immovable joints, 120. 
Imperfect joints, 121. 
lncis<>r foramen, 74. 
Incisors, 28. 
Incus, 298. 
Index (of forepaw), 99. 



INTER-TRANSVERSE. 

Indian region, 498. 

„ wild cat, 420. 
Indifferent tissue, 330. 
Individual, the physiology of, 11 
Individuation, principle of, 376. 
Inferior dental foramen, 77. 

,, ,, nerve, 273.- 

,, laterus gyrus. 269. 

,, maxillary nerve, 273. 
Infra-coccygeus, 143. 
,, orbital artery, 208 ; nerve, 73. 
,, spinatus, 148 
Infundibulum, 264. 
Infusoria, 450. 

Initial developmental changes, 318. 
Innate polar force, 377. 
Inner dorso-epitrochlear, 137. 
Innominate artery, 207. 
,, veins, 215. 

Innominatum (os), 104. 
Inorganic matter cannot support the 

cat's life, 166. 
Insectivora, 468, 472, 518. 
Insectivorous nature of primitive mam- 
mals, 516. 
Insects, 450. 

Insertion (muscular^ 128. 
Inside of cranium, 82. 
Instincts of cat, 368. 
Intellect (puts order in sense), 528. 
Intellectual powers, 372 
Intelligence (Divine), 530. 
Interarticular cartilages, 122. 
Intercondyloid fossa, 109. 
Intercostal artery, 209. 

,, vein, 217. 

Intercostals, 140. 
Interlobular veins, 188. 
Intermetacarpal ligament, 102. 
Internal annular ligament (of hind paw) 3 
162. 

„ carotid, 208. 

,, cutaneous nerve, 278. 

,, force, 525. 

,, heat, 222. 

,, iliac artery, 213. 

,, malleolus, 112. 

,, mammary artery, 209. 

„ oblique, 142. 

,, and external respiration, 221. 
Internuclear layer, 293. 
In ter-ossei of fore-paw, 152. 

,, of hind-paw, 162. 

Inter-osseous artery, 210. 
Inter-parietal, 62. 
Inter-relations of animals, 508. 
Inter-septal zone, 126. 
Inter-spinales, 139. 
Inter-spinous ligaments, 54. 
In ter-tarsal joint, 461. 
Inter-transversales, 139. 
Inter-transversarii caudae, 143. 
Inter-transverse ligaments, 54. 



INDEX. 



543 



INTER-TROCHANTERIC. 

Inter -trochanteric ridge, 107 
Inter-vertebral discs, 52. 

,, foramina, 36. 

,, substance, 36. 

•Intestine, 180. 
[Intestine (large), 182. 
flntra-lobular veins, 188. 
Intra-organic force, 380. 
•Inter-susception, 167. 
Involuntary motions, 124. 
Ireland and the wild cat, 3. 
Iris, 291. 
Irritability, 127. 
Ischiatic notches, 107. 
Ischio-cavernosus, 144. 
lschio-coccygeus, 143. 
Ischium, 105. 
Isle of Man, cats of, 7. 
Isthmus faucium, 170. 
Itch-insect of cat, 510. 
Iter et tertio ad quartum ventriculum, 267. 

Jacobson's membrane, 292. 

,, organ, 288. 

Jaguar, 397. 
J a van cat, 416. 
'Jaws (formation of), 336 
jejunum, 180. 
Jelly-fishes, 450, 453. 
Jerboas, 469. 
Jerdon cat, 415. 
Joint oil, 121. 
Joints, 120. 
Jugular foramen, 62. 

„ veins, 215. 
Juice (gastric), 179. 

,, intestinal, 181. 

,, pancreatic, 184. 
Jungle cats, 420. 

Kangaroos, 468. 
Kidney (its function), 234. 
Kidneys, 232. 

,, development of, 351. 
Kinds (what they are), 390. 

,, of food needed, 165. 

,, of language, 372. 
Kinkajous, 474. 
Knee-joint, 118. 

Knowledge and natural selection, 384. 
Kreatin, 125, 235. 
Kreatininej 125. 

Labia, 246. 
Labial glands, 170. 
Labyrinth (bony), 299. 

,, membranous, 301. 
Labyrinthodonta, 459. 
Lacerta, 461. 
Lachrymal bones, 75. 

gland, 289. 
Lacteals, 181, 218. 
Lacunas, 19. 



LIGAMENTS. 

Lambdoidal ridge, 61. 

,, suture, 60. 

Lamina spiralis, 299, 300. 
Laminae dorsales, 322. 

,, ventrales, 322. 
Lampshells, 450. 
Lancelet, 455. 

Language (its six kinds), 372. 
Large-eared cat, 417. 
Large intestine, 182. 
Laryngeal nerves, 275. 
Larynx, 223, 226. 

,, formation of, 350. 
,, its ligaments, 228. 
,, its muscles, 229. 
Lateral ethmoid, 71. 
,, ginglymus, 122. 
,, masses of sacrum, 46, 
„ ventricles, 265, 267. 
Latissimus dorsi, 137. 
Law of continuity, 443. 
Leeches, 450. 
Left auricle, 205. 

,, ventricle, 206. 
Lemurs, 468. 
Lens, 293. 
Leopard, 394. 
Leopard cat, 403. 
Lcopardus Hemandesii, 397. 
Lepidosiren, 458. 
Lesser sciatic nerve, 282. 

,, ' omentum, 190. 
Levator anguli scapulas, 145. 
,, ,, oris, 131. 

,, caudse externus, 143. 
,, ,,. internus, 143. 

,, claviculse, 148. 
,, scroti, 143. 
,, labii superioris, 131. 
„ palati, 135. 
,, palpebree, 133, 288. 
Levatores costarum, 140. 
Levers, 129. 

,, orders of, 130. 
Lewes (Mr.), 383, 384. 
Lieberkuhn (glands of), 181. 
Life (its origin experienced), 524. 
Ligamenta subflava, 53. 
Ligament (broad, of liver), 185. 
falciform, 185, 191. 
,, Poupart's, 141. 
,, round, of liver, 185, 191. 
Ligaments, 18. 

,, of ankle-joint, 118. 

,, annular of hind-paw, 162. 

,, of atlas and axis, 54. 

,, cotyloid, 116. 

,, crucial, 117. 

,, of ear ossicles, 299. 

„ elastic, 123. 

,, of elbow-joint, 101. 

of hind- foot, 118. 
of hind-leer, H6. 



544 



INDEX. 



LIGAMENTS. 

Ligaments of larynx, 228. 

,, of pectoral limb, 100. 

,, of pelvic girdle, 116. 

,, of ribs, 55. 

,, of shoulder, 100. 

of skull, 86. 
,, of spine, 52. 

„ of uterus, 247. 

,, of wrist, 102. 

Ligamentum denticulatum, 257. 
,, nuchae, 54, 123. 

,, patellae, 117. 

,, teres, 116. 

„ pit for, 107. 
Light, 494. 

Limbs (development of), 339. 
,, muscles of, 145. 
,, the skeleton of, 89. 
Limb-bones (ossification of), 340. 

,, muscles (serial homologies of), 163. 
,, skeleton (its serial homologies), 120. 
Limnofelis, 437. 
Linea aspera, 107. 
Lingual artery, 208. 
Lingula sphenoidalis, 70. 
Lining of small intestine, 181. 

,, of stomach, 179. 
Lion, 392. 

Lion's pelvis (diseased), 377. 
Lips, 170. 

Liquor sanguinis, 194. 
Liver, 184. 
„ cells, 188. 
,, formation of, 344. 
,, its function, 188. 
,, its minute structure, 187. 
living cats, 430. 
Lizard (structure of), 481. 
Llamas, 467. 

Lobes of cerebrum, 260, 264. 
,, of lungs, 224. 
„ olfactory, 260. 
Lobsters, 45*0, 452. 
Lobules of liver, 185, 187. 
Localization of sensations, 308. 
Locus perforatus anterior, 264, 265. 
Locus perforatus posterior, 364. 
Longissimus dorsi, 138. 
Long thoracic artery, 209. 
Longus colli, 135. 
Louse of cat, 510. 
Lower (tubercle of), 205. 
Lumbar nerves, 277, 281. 
,, plexus, 281. 
,, veins, 216. 
,, vertebrae, 39. 
Lumbo-sacral nerve, 281. 
Lumbricales (of fore- paw), 151. 
,, of hind-paw, 161. 

Lungs, 224. 

,, their function, 220. 
,, development of, 349. 
Lutrictis, 507, 514, 518. 



MATTER. 

Lymph, 195. 
Lymphatic ducts, 218. 

,, glands, 218. 

,, system (development of),349 

Lymphatics, 198, 217. 
Lyncus, 424. 

,, lupulinus, 426. 
Lynx, 424. 
Lvra, 265, 268. 
Lytta, 171. 

Machcerodus, 432, 491, 503, 518. 
,, and evolution, 522. 

Machines (as distinct from organisms), 

382. 
Magnum (os), 97. 
Malar bone, 74. 

,, process (of maxilla), 73. 
Malay cat, 7. 

, , , , caudal of vertebras, 46, 47. 
Male organs, 241. 
Malleoli, 112. 
Malleus, 298. 

origin of, 339. 
Malpighian corpuscles, 233. 

,, ,, of spleen, 238. 

Mammalia, 455. 
Mammalian groups, 466. 
Mammals (oldest tertiary), 514. 

,, secondary, 516. 
Mammary glands, 239. 
Man, 468. 
Manatee, 467. 
Mandible, 57, 77. 

,, ligaments of, 87. 
Mandibular symphysis, 77. 
Mangue (the), 481. 
Manis, 468. 
Manubrium, 50. 

,, of malleus, 298. 

Manul, 422. 
Manx cat, 7. 

, , , , caudal vertebrae, 46. 
Marbled tiger-cat, 404. 
Margay, 409. 
Markings of cats, 508. 
Marrow, 18. 

,, spinal, 257. 
Marsupial characters of Creodonta, 515. 
,, nature of primitive mammals ? 
515. 
Marsupialia, 468. 

Marsupials (their twofold origin ?) 516. 
Masseter, 133. 
Mastodon, 467. 
Mastoid process, 66. 
Mastoidal region, 66. 
Materialism, 385. 
Maternal conditions in, reproductive, 

326. 
Matrix, 17, 18, 20. 
Matter for nutrition, 165. 

,, to develop warmth, 165. 



INDEX. 



545 



MAXILLA. 

Maxilla, 73. 
Maxillary nerves, 273. 
Maxillary process, 336, 337. 
Maxillo -auricular, 131. 

,, turbinal, 72. 
Maximum of muscles to one digit of fore- 
paw, 153. 
,, of muscles to one digit of 
hind-paw, 163. 
Meaning of terms species, genus, family, 

&c, 520. 
Meatiofnose, 72, 287. 
Meatus auditorius externus, 64, 296. 

,, ,, internus, 66. 

Mechanism of claw's retraction, 102. 

,, of respiration, 225. 

Meckel's cartilage, 337. 
,, ganglion, 273. 
Median nerve, 278, 279. 
Mediastina, 224. 
Mediastinum testis, 243. 
Medius (of fore-paw), 99. 
Medulla oblongata, 260, 262. 

,, ,, its functions, 310. 

Medullary cavity, 20. 
,, groove, 320. 

,, sheath, 254. 

Megatherium, 468. 
Meibomian glands, 288. 
Membrana granulosa, 249. 
,, nictitans, 288. 

tectoria, 302. 
Membrane (basilar), 301. 
,, of Jacobson, 292. 

,, of Reissner, 301. 

,, Schneiderian, 287. 

,, tympanic, 297. 

Membranes (fluids passing through), 167. 
, , of nervous axis, 256. 
,, synovial, 53, 122. 
Membranous labyrinth, 301. 

,, semi-circular canals, 302. 

,, urethra, 242. 

Meningeal artery, 208. 
Mental acts, 386. 
,, foramen, 77. 
,, powers (human), 372. 
,, words, 371. 
Mesenteric artery, 211. 
„ glands, 218. 

,, veins, 216. 

Mesenteries, 189, 190. 
Mesethmoid, 71. 
Mesoblast, 320. 
Meso-cuneiforme, 115. 
Mesonyx, 505. 
Mesopiterygoid fossa, 70. 
Mesozoic mammals, 504. 

,, strata, 502. • 
Metacarpus, 98. 
Metacromion, 90. 
Metapophyses, 39. 
Metatarsus, 115. 



MUSCLES. 

Miacis, 506. 

Mice, 469. 

Microlestes, 504. 

Middle Ages and the cat, 2. 

Middle commissure, 266. 

,, fossa of skull, 83. 

,, lateral gyrus, 269. 

,, part of ear, 297. 
Migration of parasites, 509. 
Milk, 240. 

,, glands, 239. 

,, teeth, 29, 30 ; (question as to their 
origin), 517. 
Millipedes, 450. 
Mind of cat, 386. 
Minimus (of fore-paw), 99. 
Minute changes and evolution, 522. 

,, structure of liver, 187. 

,, structure of lungs, 224. 
Miocene strata, 502. 
Mites, 450. 
Mitral valve, 204. 
Mixed joints, 121. 
Mobility of spinal column, 54. 
Modes (possible) of evolution, 519. 

„ of origin (our experience concern- 
ing), 524. 
Modiolus, 299. 
Moisture, 495. 
Molars, 29. 
Molecular layers, 293. 
Moles, 468. 
Mollusca, 450, 452. 
Mombas cat, 7. 
Monocondyla, 455, 461. 
Monodelphia, 469. 
Monotremata, 468. 
Monro (foramen of), 266, 267. 
Morphological species, 391. 
Morphology, 9. 
Morsus diaboli, 247. 
Most general characters of cat, 440. 
Motion and sensation, 304. 
Motions (voluntary and involuntary), 124. 
Motor tissue, 124. 
Mouth, 170. 

,, formation o r , 342. 
Movable joints, 121.. 
Movements (amoeboid), 194. 
Mucin, 169. 
Mucous membrane, 21. 

„ „ folds of, 27 

„ ,, of nose, 287. 

,, ,, of tympanum, 299 

Mucus, 26, 169. 
Mud -fish, 458. 
Mullerian ducts, 351. 
Multifidus spinas, 139. 
Muscle fibrin, 125. 
Muscles (actions of), 129. 

,, classification of, 130. 

,, direction of, 153. 

,, origin of, 341. 



546 



INDEX. 



MUSCLES. 

Muscles stretch of, 153. 
„ of cat, 124. 
,, of fore-arm, 149. 

of ear, 131. 
,, of internal ear, 299. 
,, of the head and neck, 131. 
,, of the limbs, 145. 
, , of limbs, their serial homology, 

163. 
,, of hind-limb, 154. 
,, of larynx, 229. 
,, of the fore-paw, 152. 
,, of tongue, 134, 171. 
,, of trunk and tail, 136. 
,, maximum of to one digit, 153, 
163. 
Muscular contraction, 124, 126. 
,, fibre cells, 125. 
,, stimuli, 127. 
,, tissue, 124 ; its function, 126 ; 
(development of), 331. 
Musculocutaneous nerve, 278, 279. 

, , spiral groove, 91 ; nerve, 278, 280. 
Mustelidse, 475, 518. 
Myelon, 257. 
Mylodon, 468. 
Mylohyoid muscle, 134. 

,, nerve, 273. 

Myology, 124. 

,, of cat, its simplest expression, 
164. 
Myosin, 125. 
Myrmecobius, 504, 515. 
Myrtiformis, 131. 

Names (zoological), 392. 
Nares (formation of), 337. 

,, anterior, 59. 

,, posterior, 58. 
Nasal artery, 238. 

,, bones, 74. 

,, fossse, 86, 286. 

,, process of frontal, 64. 

,, ,, of maxilla, 73. 

Naso-frontal process, 336. 
Nates. 262. 
Native-cats, 468, 469. 
Natural selection, 520. 

,, ,, automatism and know- 

ledge, 384. 
Nature (the cat's place in), 440, 493. 

,, of nervous activity, 305. 

,, of primitive mammals, 515. 

„ of species, genera, families, &c, 
520. 
Navel, 176. 
Naviculare, 113. 
Nearctic region, 497. 
Necessity of conception of internal force, 

525. 
Neck (muscles of), 131. 

,, of femur, 107 

„ of mandible, 77. 



Nematoidea, 509. 

Neotropical region, 499. 

Nerves (anterior crural), 281, 282. 

auditory, 274, 302. 

auriculo-temporal, 273. 

axillary, 279. 

cells or corpuscles, 255. 

cervical, 277. 

chorda tvmpani, 274. 

circumflex, 278, 279. 

cranial, 269, 361. 

dental, 273. 

dorsal, 277. 

dorsal spiral, 277. 

eighth, 274. 

eleventh, 275. 

external cutaneous of pelvic limb, 
281, 282. 

facial, 274. 

fibres, 254. 

fifth pair, 271. 

of fore-limb, 278. 

fourth pair, 271. 

gastric, 275. 

genito-crural, 2S1, 282. 

glosso-pharyngeal, 274. 

gluteal, 281. 

gustatory, 273. 

hypoglossal, 275. 

ilio-hypogastric, 281, 282. 

ilio-inguinal, 281, 282. 

inferior maxillary, 273. 

internal cutaneous, 278. 

laryngeal, 275 

lumbar, 277. 

lumbo-sacral, 281. 

median, 278, 279. 

musculo-cutaneous, 278, 279. 

musculo-spiral, 278, 280. 

mylo-hyoid, 273. 
ninth, 274. 

obturator, 281, 282. 
olfactory, 270, 287. 

ophthalmic, 272. 

optic, 270. 

pathetic, 271. 

peroneal, 282. 

pharyngeal, 275. 

phrenic, 278. 

plantar, 282. 

pneumogastric, 274. 

popliteal, 282. 

pudic, 281. 

pulmonary, 275. 

radial, 280. 

respiratory of Bell, 278, 279. 

sacral, 277. 

sciatic, 282. 

seventh, 274. 

sixth, 273. 

spinal, 276. 

spinal accessory, 275. 

splanchnic, 284. 



INDEX. 



547 



NERVES. 

Nerves (subscapular), 278, 279. 

,, superior maxillary, 273. 

,, supra-scapular, 278, 279. 

„ of tail, 283. 

,, tenth, 274. 

„ third pair, 271. 

,, thoracic, 281- 

,, tibial, 282. 

,, trochlear, 271. 

„ twelfth, 275. 

,, ulnar, 278, 279. 

,, vaso-motor, 285. 

,, ventral spinal, 277. 
Nervous activity (its conditions), 307. 

,, ,, its nature, 305. 

Nervous excitement, 305. 

,, functions (summary of), 316. 

,, matter (white and grey), 256. 

,, stimuli, 305. 
Nervous system, 252. 

,, ^, its peripheral part, 269. 

,, ,, its functions, 304. 

,, ,, its origin, 355. 

Nervous tissue, 253. 

,, ,, development of, 331. 

Neural arch, 35. 

,, lamina, 35. 

,, psychosis, 386. 

,, spine, 35. 
Neurapophyses, 35. 
Neurilemma, 255. 
Neurility, 305. 
Neuroglia, 256. 

New forms (their origin experienced), 521. 
Nictitating membrane, 288. 
Nimravus, 435, 502, 518. 
Ninth nerve, 274. 

,, caudal vertebra, 47. 
Nipples, 239. 
Nitrogenous excretion, 232. 

,, foods and tissues, 166. 

Nomenclature (zoological), 392. 
Non-nitrogenous foods and tissues, 166. 
Normal forms, 490. 
Northern lynx, 424. 
Nose (cartilages of), 286. 
,, development of, 363. 
,, meati of, 287. 
,, mucous membrane of, 287. 
Notochord (its first appearance), 321. 
Nourishment of ovum, 326. 
Nuclei, 17. 
Nucleoli, 17. 

Number of kinds of cats, 431. 
Nutrition, 166. 



Obliquus capitis inferior, 135. 

,, ,, superior, 135. 

,, inferior muscle, 132. 

,, superior muscle, 132. 
Obturator artery, 213. 

„ foramen, 104, 107. 



ORGANS. 

Obturator membrane, 116. 
,, muscles, 156. 
nerve, 281, 282. 
Occipital bone, 61. 
,, foramen, 57 
ridge, 61. 
Occipito-frontalis, 131. 
Ocelot, 408. 
Ocelot-like cat, 411. 
Oculo-motor nerves, 271. 
Odontoid process, 43. 
(Esophagus, 175. 

Oldest tertiary mammal, 506, 514. 
Oleaginous substances, 166. 
Olecranal fossa, 93. 
Olecranon, 96. 
Olfactory cells, 287. 
,, fossa, 23. 

lobes, 260, 264. 
,, nerves, 270, 287. 
Olivary bodies, 263. 
Olulanus (embryos of), 510. 

,, tricuspis, 509. 
Omenta, 190. 

Omphalo-meseraic veins, 348. 
Ophiomorpha, 459. 
Ophthalmic artery, 208. 
,, nerve, 272. 

Opisthotic, 69. 
Opossums, 468, 507. 

Opponens minimi digiti ^(of fore-paw), 
152; (of hin d-paw), 162. 
,, pollicis, 152. 
Optic chiasma, 270. 

,, commissure, 264, 265. 
,, foramen, 71. 
,, nerves, 270. 

,, thalami, 268 ; their functions, 311. 
„ tracts, 263. 
Optical action of eye, 294. 
Ora serrata, 292. 
Oral and mental words, 371. 
Orbicular ligament, 101. 
Orbicularis oris, 131. 

,, palpebrarum, 131. 

Orbital muscles (actions of), 294. 

,, plate (of maxilla), 73. 
Orb ito- sphenoid, 71. 
Orbits, 57, 85. 
Orders of levers, 130. 

,, of mammals, 466. 
Organ of Corti, 302. 
,, of Giraldes, 244. 
,, of hearing, 295. 
,, of Jacobson, 288. 
,, of respiration, 220. 
,, of sight, 288. 
Organic chemistry, 12. 

,, food needed by cat, 166. 
geography^ 11. 
Organism, its definition, 9. 
Organs of circulation, 192. 
,, development of, 329. 

N N 2 



548 



INDEX, 



Organs (end), 255. 
,, generative, 240. 
,, renal, 232. 
,, of secretion, 220. 
,, of sense, 252. 
,, of smell, 28). 
,, of special sense, 285. 
,, systems of, 9. 
Oriental region, 498. 
Origin of the word cat, 2. 
,, muscular, 128. 
,, of forms as experienced, 521. 
,, of life as experienced, 524. 
„ of species, 528. 
,, of cat, 519. 
Origins of cranial nerves, 270. 
Ornate jungle cat, 420. 
Ornithodelphia, 469. 
Ornithorhynclrus, 469. 
Orycteropus, 468. 
Os calcis, 113. 
,, cuboides, 115. 
,, innominatum, 104. 
,, magnum, 97. 
,, orbiculare, 298. 
,, ,, origin of. 339. 

„ planum, 72. 
,, quadratum, 462. 
Ossicles (auditory), 298. 
Ossification, 20. 

,, of axis, 334. 

,, of backbone, 334, 

,, of cervical vertebras, 334. 

,, of limb-bones, 340. 

,, of ribs, 334. 

,, of sacral vertebrae, 334. 

of skull, 338. 
,, of sternum, 335. 

Os tincae, 246. 
Otocyon, 479, 518. 
Otoconia, 301. 
Otoliths, 301. 
Otters, 475. 
Ounce, 395. 

Our unconscious actions, 384. 
Ova (development of), 354. 
Ovarian artery, 211. 

,, ligaments, 247. 
Ovary, 248. 
,, its function, 250. 
,, development of, 352. 
Ovisac, 249. 
Ovulation, 251. 
Ovum, 250. 

,, its nourishment, 326. 
Oxen, 467. 
Oxysena, 505. 

Oxygen (exchange of), 220. 
Oxyurus com par, 509. 
Oysters, 450. 



PENGUIN. 

Pacinian bodies, 22, 23. 
Pads of cat's feet, 25. 
Paget (Sir James), 377. 
Palaearctic region, 497. 
Palaeonictis, 506, 514, 518. 
Palaeontology, 11. 
Palaeozoic strata, 502. 
Palate, 170. 

,, muscles of, 135. 
Palatine bones, 75. 

,, plate (of maxilla), 73. 
Pale nerve fibres, 255. 
Palmar arch, 210. 

,, . fascia, 149. 
Palmaris longus, 149. 
Pampas cat, 423. 
Pancreas, 183. 

,, formation of, 344. 
,, of Aselli, 219. 
Pancreatic juice, 184. 
Panda (the), 475. 
Panniculus carnosus, 136. 
Panther, 394. 
Papillae, 22. 

,, circum vallate, 172. 

,, cervical, 172. 

,, flattened, 172. 

,, fungiform, 172. 
Parachordal cartilage, 337. 
Paradoxures, 481. 
Paraguay cat, 7. 
Parasites of cats, 509. 
Parasphenoid, 457. 
Pardalina WaricicJcii, 410. 
Pardine lynx (the), 426. 
Parenchyma of body, 9, 165. 
Parepididymis, 244. 
Parietal bone, 62. 
Paroccipital process, 62. 
Parotid gland, 172. 
Parovarium, 250. 
Parturition, 217. 
Par vagum, 274. 
Pasht, 3. 
Patella, 109. 

,, ligaments of, 117. 
Pathetic nerves, 271. 
Patriofelis, 506. 
Paws, veins of, 216. 
Pectineus, 157. 
Pectoral limb (skeleton of), 89. 

,, limb, general view of its skele- 
ton, 102. 
Pectoralis, 145. 
Pedicle of vertebra, 35. 
Pedigree of cat, 512, 517, 518. 
Peduncles of cerebellum, 262. 

of olfactory lobes, 264, 270. 
Pelvic girdle (articulation and ligaments 
of), 116. 
„ limb (skeleton of), 103. 
Pelvis, 104. 
Penguin, 462. 



INDEX. 



549 



PENIS. 

Penis, 241. 

,, development of, 352. 
Penniforni muscles, 128. 
Pentastoma denticulatum, 510. 
Peptic glands, 179. 
Peptone, 180. 
Pere David, 6. 

Perforated transverse processes, 41. 
Pericardium, 199. 
Perichondrium, 18 
Perilymph, 301. 
Perimysium, 125 
Periosteum, 18. 
Periotic, 69. 

Peripheral part of nervous system, 269. 
Periplast. 330. 
Peristaltic action, 181. 
Peritoneal cavity formed, 322. 
Peritoneum, 189. 

,, development of, 345. 

,, general view of, 191. 

Peroneal artery, 213. 
,, nerves, 282. 
Peroneus brevis, 160. 
,, longus, 159. 
,, quinti digiti, 160. 
Persian cat, 6. 
Petit (canal of), 294. 
Petrosal, 66. 
Petrous bone, 66. 
Peyer's patches, 181. 
Phalangers, 468. 
Phalanges, 99, 116. 
Pharyngeal nerves, 275. 
Pharynx, 174. 

,, constrictor muscles of, 135. 
Phascogale, 516. 
Phascolotherium, 504. 
Phrenic artery, 209. 
,, nerve, 278. 
,, veins, 216. 

Phylogeny, 11, 512. 

,, of iEluroidea, 514. 

Physical conditions, 494. 

Physical forces and nerve action, 306. 
Physiological species, 391. 
Physiology, 10. 

,, of the individual, 11. 

Pia mater, 256, 261. 

Pillars of fauces, 170. 

Pineal gland, 262, 266. 

Pinna, 295. 

Pinnipedia, 468, 473. 

Pisces. 456. 

Pisiform bone, 96. 

Pith of hair, 23. 

Pit for ligamentum teres, 107. 

Pituitary body, 264. 

fossa, 33, 69. 

Pivot joints, 122. 

Place in nature of cat, 440, 493. 

Placenta, 327. 

Plane of cribriform plate, 85. 



PEEZTGAPOPHYSES. 

Plane of foramen magnum, 85. 
Planiform joints, 122. 
Plantar nerves, 282. 
Plantaris, 160. 
Platysma myoides, 131. 
Pleasure and pain, 314. 
Pleurae, 224. 
Plexus (brachial), 278. 
,, cervical, 277. 
,, lumbar, 281. 
,, sacral, 281. 
Plexuses of sympathetic, 284. 
Plica semilunaris, 288. 
Pliocene strata, 502. 
Pneumogastric, 274. 
Pogonodon, 437, 502, 518. 
Poisonous gases, 221. 
Polar vesicles, 318. 

t , vital force, 377. 
Polecats, 469. 
Pollex, 99. 
Polyzoa, 450. 
Pons varolii, 260. 
Popliteal nerves, 282. 
Popliteus, 161. 

,, depression for, 108. 
Porcupines, -469. 
Pores, 22. 
Porpoises, 467. 
Portal canals, 187. 
,, fissure, 185. 
,, system, 216. 
, , vein, 187. 
Portio dura, 270, 274. 
„ mollis, 270, 274. 
Poms opticus, 292. 
Position of cat's genus, 489. 

,, of viscera in body cavity, 176. 
Posterior commissure, 267. 

,, fossa of skull, 83. 

,, hyoidean cornua, 77. 

,, nares, 58. 

,, palatine foramen, 76. 
Post-glenoid foramen, 67. 

,, process, 65. 

Post-orbital ligament, 87. 

, , process of frontal, 63. 

Post tragus, 296. 
Postzygapophyses, 36. 
Potential life, 524. 
Potomogale, 468. 
Pouched beasts, 468. 
Poupart's ligament, 141. 
Powers of plants, 376. 
Pregnancy, 247. 
Premammalian ancestors of cat unknown, 

518. 
Premaxilla, 73. 
Premolars, 28. 

Preorbital process of frontal, 64. 
Presphenoid, 70. 
Presternum, 50. 
Prezygapophyses, 35. 



550 



INDEX. 



PRIMARY. 

Primary strata, 502. 
Primates, 468, 472. 
Primitive mammals insectivorous? 516. 

,, marsupial ? 515. 

Primordial era, 254. 
Principle of developmental changes, 387. 

,, of individuation, 376. 
Principles of zoological classification, 

449. 
Procehirus, 435, 514, 518. 
Proboscidea, 467, 472. 
Process (acromion), 90. 
,, coracoid, 90. 
,, coronoid of mandible, 77. 
,, ensiform, 50. 
,, hamular, 70. 
,, mastoid, 66. 
,, nasal, 64. 
,, naso-frontal, 336. 
,, odontoid, 43. 
,, post-glenoid, 65. 
,, post-orbital of frontal, 63. 
,, pre-orbital, 64. 
,, of respiration, 220. 
,, xiphoid, 50. 
Processes (vertebral), 35. 
Processus a cerebello ad testes, 262. 
Processus gracilis, 298. 

„ lenticularis, 298. 
Procyonidae, 474. 
Products of waste, 232. 
Profunda artery, 210. 
Promontory.. 63, 298. 
Pronation and supination, 102. 
Pronator quadratus, 151. 

,, teres, 149. 
Pronuclei (male and female), 318. 
Prootic, 69. 
Prostate gland, 242. 
Protein, 12. 

Proteles, 475, 483, 518. 
Proteus, 459. 
Protoplasm, 12, 329. 
Prototypal ideas, 529. 
Protovertebrse, 325, 33 
Protractor muscles, 129. 
Protrusion and retraction of claws, 102. 
Provinces of Vertebrata, 455. 
Proviverra, 505, 514, 518. 
Pseudcelurus, 434, 502, 518. 
Psoas iuagnus and parvus, 156. 
Psyche, 380, 386. 

,, its functions, 382. 
Psychical powers of cat, 366, 370. 
Psychogenesis, 526. 
Psychology, 11, 365. 

,, and development, 389. 

Psychoses, 386. 
Pterodon, 505, 514, 518. 
Pteropods, 450. 
Pterygoid, 70. 

,, muscles, 133. 
Pubis, 106. 



RENAL. 

Pubo-coccygeus. 143. 
Pudic artery, 213. 
,, nerve, 281. 
Pudu humilis, 490. 
Pulex cati, 510.- 
Pulkny of eye muscle, 132. 
Pulmonary artery, 206. 

„ circulation, 203. 

,, nerves, 275. 

,, veins, 214. 

„ vesicles, 223. 

Puma, 397. 

Puncta lachrymalia, 288, 289. 
Purpose, 527. 
Pylorus, 178. 
Pyramidalis, 131. 
Pyramids of medulla, 263. 
Pyriformis, 156. 



Quadratus fern oris, 156. 

,, lumborum, 156. 

Quadriceps extensor, 158. 
Quagga, 467. 

Quasi-intelligence of cat, 367. 
Quasi-valvulse conniventes, 176. 



Rabbits, 469. 
Racoons, 474. 
Radial artery, 210. 

„ nerve, 280. 

,, symmetry, 453. 
Radiation of sensations, 310. 
Radiolarians, 378, 450. 
Ra.dius, 93. 
Rami of mandible, 77. 
Ran a, 459. 

Rational science, 529. 
Rat-moles, 469. 
Rats, 469. 

Realities (immaterial), 385. 
Receptaculum chyli, 218. 
Reciprocal influence of soul and body, 

383. 
Recti-muscle of eye, 132. 
Recto-coccygeus, 144. 
Rectus abdominis, 142. 

„ capitis anticus major, 135. 

ft ,, ,, minor, 135. 

,, capitis posticus major, 135. 

„ „ ,, minor, 135. 

„ femoris, 158. 

,, lateralis, 135. 
Red corpuscles, 194. 
Reflex action, 310. 
Regions of skull, 60. 

,, of general zoological geography, 
497. 
Reissner's membrane, 301. 
Renal artery, 211. 

,, organs, 232. 

,, veins, 216. 



INDEX. 



551 



EEPEODTCTIOX. 

Reproduction, 240. 
Eeptilia, 455, 461 
Reserve air, 226. 

Respiration (internal and external), 220. 
,, system of, 220. 

,, its mechanism, 225. 

,, of embryo, 327. 

Respiratory nerve of Bell, 278, 279. 
Restiforni bodies, 262. 

,, tract, 263. 
Rete mucosum, 22. 

,, vasculosum, 244. 
Retia mirabilia, 196. 
Retina, 292. 

Retraction of claws, how effected, 102. 
Retractor muscles, 129. 

,, penis, 144. 
Retraheutes auricularis, 132. 
Revolutions of cochlea, 300. 
Rhinencephalic fossa, 83. 
Rhinoceroses, 467, 507. 
Rhizopoda, 450, 454. 
Rhomboidei, 145. 
Ribs, 50. 
,, angles of, 52. 
,, ligaments of, 55. 
,, ossification of, 334. 
,, true and false, 50. 
Right auricle, 205. 

,, ventricle, 205. 
Rigor mortis, 128. 
Rima glottidis, 229. 
Ring (abdominal), 141, 143. 
,, and collar joints, 122. 
Ripening of ova, 251. 
Rodentia, 468, 472. 
Rodents, 469, 507. 
Rods of Corti, 302. 

,, and cones, 292, 293. 
Romans and the cat, 2. 
Rook (structure of), 462. 
Roots of lungs, 224. 
Rostrum of sphenoid, 70. 
Rotator muscles, 128. 
Rotatores spina?, 139. 
Rotifera, 450. 
Round ligament of liver, 185, 191. 

,, ,, of uterus, 247. 

Rugae, 27 

,, of palate, 170. 
Running, 129. 
Rustv-spotted cat, 413. 
Rytlim, 226. 
Ryzsena, 481. 



Saccule, 301. 
Sacral foramina, 45. 

,, nerve, 277. 

,, plexus, 281. 

,, vertebra? (ossification of), 334. 
Sacro-coccygeus, j 43. 

,, iliac synchondrosis, 116. 



SENSE. 

Sacro-lumbalis, 138. 

Sacrum, 44. 

Saddle -shaped surfaces, 122. 

Sagitta, 450. 

Sagittal suture. 60. 

St. Augustine, 527 

St. Hilaire (Isid. Geof.), 377. 

Saliva, 174. 

Salivary glands, 172; formation of, 344. 

,, papilla, 172. 
Sarcolemma, 125. 
Sarcoptes cati, 510. 
Sartorius, 157. 
Scala media, 301. ^ 
Scala? of cochlea, 300. 
Scaleni muscles, 134. 
Scallops, 450. 

Scaphoid (of hind foot), 113. 
Scapho-lunar bone, 96. 
Scapula, 89. 
Schindylesis, 121. 
Schneiderian membrane, 287. * 
Schwann (white substance of), 254. 
Sciatic nerves, 282. 
Science, a knowledge of causes, 530. 

,, rational, 529. 
Sclerotic, 289. 
Scorpions, 450. 
Scotland and the wild cat, 3. 
Scrotum, 243. 
Sea-anemone, 450. 
Sea-bears, 468. 
Seals, 467, 468. 
Sea-mice, 450. 
Sea-urchins, 450, 453. 
Sebaceous glands, 24. 
Second pair of nerves, 270. 

,, visceral arch, 338, 339. 
Secondary creation, 527. 

,, fossil mammals, 504, 516. 

,, strata, 502. 
Secretion (its relation to nutiition), 166 

,, system of, 220. 

,, its nature, 230. 
Sectorial teeth, 28, 29. 
Seeds and vitality, 524. 
Segmentation, 329. 

of yelk, 318. 
Sella turcica, 69. 
Semicircular canals (osseous), 300. 

,, membranous, 302. 

Semilunar ganglia, 284. 

,, ' valves, 204. 
Semi-membi*anosus, 158. 
Semi-penniform muscles, 128. 
Semi-spin alis, 139. 
Semi-tendinosus, 158. 
Sensation, 253. 

,, and motion, 304. 

Sensations (their localization), 308. 

,, external and internal, 313. 

,, are causes, 383. 

Sense (organs of), 252, 285. 



552 



INDEX 



SENSE. 

Sense of hearing, 315. 
„ of sight, 315. 
,, of smell, 315. 
,, of taste, 315. 
„ of touch, 314. 
Sensitivity, 374. 
Sensu.s communis, its site, 311. 
Septal line, 126. 
,, zone, 126. 
Septum of tympanic cavity, 67. 

,, lucidum, 266. 
Serial homologies of limb muscles, 163. 
,, ,, of limb skeleton, 120. 

,, symmetry, 15. 
Series (the whole vertebral), 47. 
Serratus magnus, 145. 
,, posticus, 138. 
Sertularians, 450. 
Serum, 194. 
Serval, 406. 
Servaline cat, 408. 
Sesamoid bones, 99. 
Seventh cervical vertebra, 42. 

,, nerve, 274. 
Sex, 240. 
Sexual organs, 241. 

,, ,, of the sexes (fundamental 
resemblances of), 354. 
Shaw's cat, 421. 
Sheep, 467. 
Shrews, 468. 
Shrimps, 450. 
Siamese cat, 6. 

Side view of skull described, 81. 
Sight, 315. 

,, organ of, 28?. 
Sigmoid cavities of ulna, 96. 
Simplest expression of cat's myology, 164. 
Sinus pocularis, 242, 354. 

,, venosus, 205, 347. 
Siren, 459. 
Sirenia, 467, 471. 
Site of the " common-sense," 311. 
Sixth cervical vertebra, 42. 
,, nerve, 273. 
,, rib, 50. 
Skeleton, what it is, 16. 

,, appendicular, 34, 39. 
,, axial, 34. 
,, of head, 56. 
,, of head and trunk, 34. 
„ of the limbs, 89. 
,, of fore and hind limbs (differ- 
ences and correspondences), 
119. 
,, of pelvic limb, 103. 
,, spinal, 34. 
,, of thorax, 49. 
Skin, 21. 

,, muscles of, 136. 
Skull, 56. 

,, development of, 335. 
,, viewed in front, 79. 



SPINAL. 

Skull viewed internally, 82. 

,, viewed laterally, 81. 

,, viewed ventrally, 79. 

,, transversely bisected, 85. 

,, vertically bisected, 83. 

,, cavities of, 85. 

,, generalized view of, 87. 

, , ligaments of, 86. 

,, ossification of, 338. 

,, regions of, 60. 
Sleep, 313. 
Sloths, 468. 
Small cat, 415- 
Small-eared cat, 417. 
Smell, 315. 

,, organs of,- 286. 
Snails, 450. 
Sneezing, 226. 
Sockets of teeth, 27, 
Soft commissure, 268 

,, palate, 170. 
Solar plexus, 284. 
Solenodon. 468. 
Soleus, 161. 
Somatopleure, 322. 
Soul, 380. 

,, its functions, 382. 

,, and body (reciprocal action), 383. 
Special senses«(organs of), 285. 

,, sensitive faculties, 314. 
Specialized forms, 490. 
Species (a), 391. 

,, development of, 512. 

,, morphological and physiologi- 
cal, 391. 

,, what it really is, 520. 
Specific names, 392. 
Speech, 371. 

Sperm- cell and germ-cell, 318. 
Spermatic artery, 211. 
,, cord, 243. 
,, fascia, 243. 
,, filaments, 245. 
,, veins, 216 
Spermatozoa, 245. 

,, their action, 318. 

Sperm ospores, 245. 
Spheno-paiatine foramen, 76. 

,, ganglion, 273. 

Sphenoid, 69. 
Sphenoidal fissure, 70. 

„ sinuses, 70, 86. 
Spherical aberration, 295. 
Spheroidal epithelium, 26. 
Sphincter ani, 144. 

,, muscles, 128. 
Spiders, 450. 
Spigelian lobe, 185. 
Spinal accessory nerve, 275. 

,, cord, 257. 

,, cord (commissures of), 259. 

,, cord (its functions), 309. 

,, marrow (development of), 356. 



INDEX. 



553 



Spinal nerves, 276. 

,, nerves (their functions), 307. 

„ skeleton, 34, 35. 
Spinalis colli, 138. 
Spine of ischium, 106. 
Spinous processes, 35. 
Splanchnic nerve, 284. 
Splanchnopleure, 322. 
Spleen, 238. 

,, formation of, 350. 
Splenic artery, 211. 

,, vein, 217. 
Splenius, 135. 
Spermatic cord, 243, 245. 
Spongida, 450. 
Spongy urethra, 242. 
Spot (germinal), 250. 
Spotted cat of Fontaneir, 400. 
Springing. 129. 
Squamosal, 64. 
Squamous suture, 63. 
Squirrels, 469. 
Stapedius, 61, 299. 
Stapes, 298. 

,, origin of, 339. 
Star-fishes, 450, 453. 
Stellate ligaments, 55. 
Steno's duct, 172. 
Stenson's duct, 172. 
Steppe cat, 421. 
Stercorin, 188. 
Stereoguathus, 504. 
Stemalis, 142. 
Sternebra?, 50. 
Sterno-hyoid, 134. 
Sterno-mastoid, 134. 
Sterno-thyroid, 134. 
Sternum, 49. 

,, ossification of, 335. 
Stimuli, 305. 

,, of muscle, 127. 
Stomach, 177. 

,, function of, 179. 
Stomata, 217. 
Strata of the earth, 501. 
Straw cat, 423. 
Stretch of muscles (pectoral limb), 153. 

,, ,, (pelvic limb), 162 

Striped muscular tissue, 125. 
Stroma (of ovary), 248. 
Strongylus tubseformis, 509. 
Structural nervous elements, 254. 
Structure (minute, of liver), 187. 

,, of stomach, 179. 
Stump-tailed cats, 7. 
Stylo-glossus, 134. 
Stylo-hyal, 78. 
Stylo-hyoid, 133. . 
Stylo-mastoid foramen, 65. 
Stylo-maxillary ligament, 87. 
Stylo-pharyngeus, 134. 
Styloid process of radius, 94. 

,, „ of ulna, 96. 



SYSTEM. 

Stypolophus, 505. 

Subclasses and orders of mammals, 466. 

Subclavian artery, 209. 

,, vein, 215. 

Submaxillary gland, 173. 
Subscapular nerves, 278, 279. 
Subscapularis, 148. 
Substance (material and immaterial), 378. 

of teeth, 31. 
Succession of teeth, 32. 
Sulci, 261, 268. 

Summary of alimentary processes, 168. 
,, of cat's pedigree, 517. 
,, of cranial nerves, 275. 
,, of fossil cats, 438. 
,, of nervous functions, 316. 
Superficial fascia, 143. 
Superior dental artery, 208. 
,, lateral gyrus, 268. 
,, maxillary nerve, 273. 
,, thoracic artery, 209. 
,, vena cava, 215. 
Supernumerary digits, 377. 
Supination and pronation, 102. 
Supinator brevis, 152. 
,, longus, 151. 
Supplemental air, 226. 
Support of the body, 129. 
Supra-condj-loid foramen, 91. 
Supra-occipital, 61. 
Supra -orbital sulcus, 269. 
Supra-renal artery, 211. 
,, capsules, 237. 

,, ,, development of, 351. 

Supra-scapular nerve, 278, 279. 
Supra-spinatus, 148. 
Supra-spinous ligaments, 54. 
Supra-tragus, 296. 
Suricate (the), 481. 
Suspensor oculi, 132. 
Suture (squamous), 63. 
Sutures, 57, 60, 121. 
Sweat-glands, 22. 
Sylvian fissure, 264, 269. 
Symmetry, bilateral, 15. 

,, serial, 15. 

Sympathetic system, 283. 

,, ,, its functions, 312. 

Symphysis pubis, 106. 

,, of mandible, 77. 
Synarthroses, 120. 
Synesthesia 386. 
Sjmovia, 53. 121. 
Synovial capsules, 122. 

,, membranes, 53. 
Syntonin, 125. 
System (co-ordinating), 253. 
,, muscular, 124. 
,, nervous, 252. 
,, osseous, 34. 
,, portal, 216. 
,, of respiration, 220. 
,, of secretion, 220. 



554 



INDEX. 



SYSTEM. 

System (sympathetic), 2S3. 

,, vascular, 192. 
Systemic circulation, 203. 

,, veins, 214. 
Systems of organs, 9. 

Tadpole, 523. 

Taenia crassicollis, 509, 510. 

„ elliptica, 509, 510. 

,, gemiteres, 509. 

„ lineata, 510, 519. 

,, litterata, 509, 510 
Tamiada, 509. 
Tail (muscles of), 143. 

,, nerves of, 283. 
Tapetum, 291. 
Tape-worms, 450, 50-9. 
Tapirs, 467, 507. 
Tarsus, 113. 
Tasmanian wolf, 468. 
Taste, 315 ; organ of, 285. 
Taurec, 468. 
Taxonomy, 11, 467. 
Teats, 239. 
Teeth of cat, 27. 

,, formation of, 343. 

,, their functions, 171. 
Temporal bone, 64. 
lobe, 264. 
,, muscle, 133. 
Temporo-auricular, 131. 
Tendo Achillis, 160. 

,, ,, groove for, 113. 

Tensor tympani, 299. 

,, vagina? femoris, 154. 
Tenth caudal vertebra, 47. 

,, dorsal vertebra, 38. 

,, nerve, 274. 
Tentorium, 256. 
Tenuissimus, 158. 
Teres major, 148. 

,, minor, 148. 
Tertiary strata, 501, 502. 
Testes, 243, 262. 

,, development of, 352. 
Theistic idea (the), 527. 
Thibet lynx, 426. 

,, tiger-cat, 400. 
Thigh (glands of), 218. 

,, muscles of, 154. 
Third eyelid, 288. 

,, branch of trigeminal, 273. 

,, pair of nerves, 271. 

,, ventricle, 265, 266. 

,, visceral arch, 338, 339. 
Thoracic aorta, 210. 
„ duct, 288. 
,, nerves, 281. 
Thorax (skeleton of), 49. 

,, as a whole, 52. 
Thoughts (their oral expression), 
Thread-worms, 450. 
Thylacine, 468. 



372. 



TRTCKS. 

Thylacinus, 516. 
Thymus, 237. 

,, gland (development of), 350. 
Thyro-hyal, 78, 134. 

,, hyals (origin of), 339. 

,, hyoid, 134. 
Thyroid axis, 209. 

,, body, 237 ; development of, 350. 
,, cai 
Tibia, 110. 
Tibial artery, 213. 

,, nerves, 282. 
Tibialis auticus, 159. 

,, posticus, 162. 
Tics, 450. 
Tidal air, 226. 
Tiger, 393. 

Time and the Felidse, 501. 
Tissue, what it is, 9. 

,, adipose, 17, 18. 

,, areolar, 22. 

,, cartilaginous, 18. 

,, connective, 16, 17. 

,, elastic, 17. 

,, epithelial, 21. 

,, erectile, 242. 

,, muscular, 124. 

,, nervous, 253. 

,, osseous, 19. 
Tissues (development of), 329. 
Tongue, 171. 
Tonsils, 170. 
Tooth substance, 31. 

,, succession, 32. 
Tortoiseshell cats, 6. 
Touch, 314. 

,, organ of, 285. 

,, corpuscles, 22, 23. 
Trabeculos (of penis), 242. 

,, cranii, 337. 
Trachsea, 223. 
Tracheal gland, 218. 
Tragus, 296. 

Transference of sensations. 310. 
Transformations of substance, 165. 
Trans versalis, 142. 

,, cervicis, 138. 

Transverse colon, 182. 
,, process, 35. 

,, processes perforated, 41. 

Transversus perenpei, 144. 
Trapezium, 97. 
Trapezius, 137. 
Trapezoides, 97. 
Trematoda, 450, 509. 
Trepang, 450. 
Triangularis sterni, 141. 
Triceps, 149. 
Trichina spiralis, 509. 
Trichodectes subrostratus, 510. 
Trichosoma cati, 509. 
Tricipital muscles, 128. 
Tricks played with language, 443. 



INDEX. 



555 



TRICUSPID. 

Tricuspid valve, 204. 
Trigeminal nerves, 271. 
Trigone, 235. 
Trochanters, 107. 
Trochlea of humerus, 93. 
Trochlear nerves, 271. 
Trucifelis, 438. 
True molars, 29. 
,, ribs, 50. 
,, vertebra?, 36. 
,, vocal cords, 229. 
Trunk (muscles of), 136. 
Tuber cinereum, 263. 
Tubercle of Lower, 205. 

,, of tibia, 112. 
Tubercular surfaces of vertebrae, 38. 
Tuberculum of ribs, 50. 
Tuberosities of humerus, 92. 

,, of tibia, 112. 

Tuberosity of ischium, 106. 
,, of maxilla, 73. 

,, of os calcis, 113. 

,, of radius, 93. 

Tubes (bronchial), 225. 
Tubeworms, 450. 
Tubuli recti, 244. 
,, seminiferi, 243. 
,, uriniferi, 233. 
Tunica albuginea, 243. 
,, fibrosa, 249. 
,, granulosa, 250. 
,, Ruyschiana, 291. 
„ vaginalis, 243. 
Tunicata, 450, 453. 
Tunicates, 523. 
Tupaias, 468. 
Turbellaria, 450. 
Turbinal (ethmo), 71. 

,, (maxillo), 72. 
Twelfth nerve, 275. 
Twofold origin of Marsupials ? 516. 
Tympanic, 65. 

,, cavity, 67. 

,, membrane, 297. 

Tympano-hyal, 65. 

,, ,, cartilage of, 78. 

Tympanum, 297. 

,, its mucous membrane, 299. 

Type of Aves, 462. 
,, of Batrachia, 459. 
,, of fishes. 456. 
,, of reptilia, 461. 
,, of species, 390. 
Types, utility of their study, 530. 
Typical forms, 490. 



Ulna, 95. 
Ulnar artery, 210. 

,, nerve, 278, 279. 
Umbilical cord, 327. 
,, fissure, 185. 
,, veins, 348. 



Umbilical vesicle, 325. 
,, vessels, 327. 
Umbilicus, 176. 
Unciform bone, 97 
Unconscious actions (our), 384. 
Ungukta, 467, 472. 
Unstriped muscular tissue, 125. 
Urachus, 235, 351. 
Urea, 232. 
Ureters, 233, 235. 
Urethra, 242. 
Urinaiy organs, 350. 
Urine, 235. 
Urogenital sinus, 351. 
Ursidse, 474, 518. 
Uterine artery, 213. 
Uterus, 246. * 

,, its ligaments, 247. 
Utility of studying types, 530. 
Utricle, 242, 301, 354. 



Vacuolatton, 329. 
Vagina, 246. 

, , and uterus (development of), 352. 
Valve of Vieussens, 262. 

,, ileo-esecal, 183. 
Valves of heart, 204. 

,, of veins, 196. 
Valvulse conniventes (quasi), 176. 
Variety (a), 391. 
Vas aberrans, 244. 
,, deferens, 244. 
Vasa etferentia, 244. 

,, recta, 244. 

,, vasorum, 196. 
Vascular system, 192. 
Vaso-motor nerves, 285. 
Vastus externus, 158. 

,, internus, 159. 
Vegetal functions, 10. 

,, powers, 376. 

,, psychosis, 386. 
Veins, 196, 214. 

,, axillary, 215. 

,, azygos, 217. 

,, brachial, 215. 

,, bronchial, 225. 

,, capsular, 216. 

,, cardinal, 347. 

,, caudal, 216. 

,, development of, 346. 

,, femoral, 216. 

,, hepatic, 187. 

,, iliac, 216. 

,, innominate, 215. 

,, intercostal, 217. 

„ jugular, 215. 

,, lumbar, 216. 

,, mesenteric, 216. 

,, minute, of liver, 188. 

,, omphalo-meseraic, 348. 

,, of paws, 215. 



556 



INDEX. 



VEINS. 

Veins (phrenic), 216. 
,, portal, 187. 
,, pulmonary, 215. 
,, renal, 216. 
,, spermatic, 216. 
,, splenic, 217. 
,, subclavian, 215. 
,, systemic, 214. 
,, umbilical, 348. 
,, vertebral, 215. 
Velum interpositum, 266. 

,, palati, 170. 
Vena cava superior, 216. 
Venpe cavse, 216. 

,, comites, 196. 
Venous blood, 195. 
Ventral common ligament, 52. 
,, plates, 322. 
,, skeleton, 49. 
„ spinal nerves, 277. 
Ventricles of brain, 260, 265. 
,, of heart, 205. 
„ of larynx, 229. 
Verification, 381. 
Vermes, 450, 509. 
Vermicular motion, 181. 
Vertebra, 35. 

,, atlas, 44. 
,, axis, 43. 
,, dentata, 43. 
Vertebrae (caudal), 46. 
,, cervical, 40. 
,, dorsal, 36, 37. 
,, lumbar, 39. 
,, sacral, 44. 
,, true and false, 36. 
Vertebral artery, 209. 

,, canal, 35 ; of transverse pro- 
cesses, 41. 
,, categories, 36. 
,, epiphyses, 334. 
,, grooves, 48. 
,, processes, 35. 
,, series, 47. 
,, vein, 215. 
Vertebrata, 451, 455. 
Vertebrate groups, 455. 
Verum montanum, 242. 
Vesica prostatica, 242. 
Vesical artery, 213. 
Vesicle (germinal), 250. 
Vessels (absorbent), 217. 
Vestibular nerve, 302. 
Vestibule, 246. 

,, of ear, 299. 
Vibratile cilia, 25, 175. 
Villi of intestine, 181. 
Viscera (their relative positions), 176. 
Visceral arches, 326. 

„ ,, the first, 337, 338. 

,, ,, second, 338, 339. 

,, third, 338, 339. 
„ ,, (formation of), 335. 



ZONA, 

Visceral clefts, 3S6. 
Viscero-skeletal muscles, 130. 
Vital capacity, 226 

,, force and nervous activity, 306. 

,, innate force (polar), 377. 
Vitelline duct, 327. 
Vitreous humour, 293. 
Vive rriceps planiceps, 417. 
Viverridte, 475, 488, 481, 518. 
Viverrine origin of cats, 513. 
Vocal cords, 227, 229. 
Voice, 229. 

Voluntary motions, 124. 
Vomer, 76. 



Wag ati, 404. 
Walking, 129. 
Warm-bloodedness, 222. 
Waste, 166. 

,, products, 232. 
Water lost in respiration, 222. 
Weasels, 468, 475. 
Whales, 467. 
Wharton's duct, 173. 
What is a cat ? 440, 493. 
Wheel animalcules, 450. 
Whelks, 450. 
Whiskers of cat, 24. 
White corpuscles, 194. 

,, nerve-fibres, 254. 

,, nervous matter, 256. 

,, substance of Schwann, 254. 
Wild cat, 4. 

,, ,, distribution of, 3. 

,, ,, gestation of, 8. 

,, ,, and Ireland, 3. 

,, ,, in Scotland, 3. 
Willis (circle of), 209. 
Winslow (foramen of), 190. 
Wombat, 468. 
Wool, 23. 

Woolfian bodies, 350. 
Woolly cheetah, 429. 
Word (the oral and mental), 371. 
" Worm " of the tongue, 171. 
Worms, 450. 

of cat, 509. 



Xiphoid process, 50. 



Yaguarondi, 412. 

Yawning, 226. 

Yelk (its segmentation), 318. 



Zibet, 481. 

Zona pellucida, 250. 



INDEX. 



557 



ZOOLOGICAL. 

Zoological groups (their real nature), 
520. 
,, nomenclature, 392. 
Zoology, 8. 
Zoomorphism, 527. 
Zootomy, 10. 
Zygapophyses, 35. 



ZYGOMATO. 

Zygencephala, 455. 
Zygoma, 58. 
Zygomatic glands, 173. 
,, process, 64. 

Zygomaticus, 131. 
Zygomato-auricularis, 132. 



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